Staying a Healthy Vegan Source

The vegan diet (a diet without animal flesh, fish, eggs, or dairy) appears to be a relatively new experiment in the history of human eating. It has only been since the mid-1940s that it has been practiced in an organized fashion in the Western world. So far, the experiment appears to be successful: vegans in developed countries have been shown to have the same overall mortality rates as meat-eaters with healthy lifestyles (low smoking and alcohol intake).² These mortality rates (deaths per year before age 90) are about 50% lower than those of the general population.² However, there are areas where vegans' health can be improved.

This article has three purposes:

To help people make the transition to a vegan diet.
To give accurate information about the known health benefits of a vegan diet.
To give vegans specific recommendations in order to maximize their health both for themselves and for improving the results of health studies on vegans.

I also wrote this article to provide information that other Vegan Outreach members and I wish we had known when we became involved in promoting veganism.

I was vegan for awhile, but...

Vegan Outreach promotes a vegan diet in order to lessen the suffering of animals. Since the average American consumes thousands of animals over the course of a lifetime, each person who goes vegan makes a difference by removing their support from the factory farming and slaughtering of these animals. For this reason, I have been involved in vegan advocacy for over a decade.

During my years of outreach, I have been told by many people that they tried to be vegetarian or vegan, but hadn't felt healthy. I found this troubling. How can we prevent animal suffering by promoting a vegan diet for our society if some people do not respond well to it? Finding an answer to this problem was a major motivation for my becoming a Registered Dietitian. In researching the subject, I discovered that some claims about the vegan diet include distortions or omissions which can lead to people having poor experiences.

For example, some vegan advocates emphasize that humans need only small amounts of B12 and that it can be stored in the body for years. It is true that, at the time they become vegan, some people have enough B12 stored in their liver to prevent serious B12 deficiency for many years. However, people often misinterpret this to mean that you only need to consume a tiny amount of B12 once every few years. Actually, to build up such stores, it takes many years of consuming B12 beyond one's daily needs. Many people do not have large enough stores of B12 to be relied upon even for short periods. This is an easy problem to solve by simply eating B12-fortified foods or taking a supplement.

Nutritional myths have a way of going from one extreme to the other. For example, people once believed that in order to rely on plant protein, you had to combine particular foods at every meal. We now know this is not true. But in countering this myth, claims have gone from "You don't need to combine proteins," to "It's easy to get enough protein on a vegan diet;" to the harmful "It's impossible not to get enough protein!"

On average, vegans get enough protein. In fact, many people trying a vegan diet may choose foods that are high in protein without knowing it. Others may randomly choose foods that are not high in protein. Personally, since I do not feel right when I'm not eating at least a few protein-rich foods each day, I can see how someone else might be ready to quit a vegan diet after a few days of not consuming some protein-rich foods. I fear that many people quickly give up on a vegan diet, thinking it made them feel bad, instead of realizing they might have felt differently had they eaten more protein-rich foods.

This is not to say that every person does better with more protein. Some people report feeling better eating less protein. There are many differences among people and how they respond to various foods.

Eating enough calories might be an issue for an uninformed person who decides to give the vegan diet a try for a few days. Someone on the standard Western diet may only be aware of vegan foods that are low in calories (e.g., salads, vegetables, fruits). Eating only these foods for a day might leave someone unsatisfied and thinking the vegan diet is to blame, when all they needed to do was eat more high-calorie foods.

Again, not everyone needs calorie-dense foods. Some people enjoy the fact that when eating low-calorie foods, they can eat more frequently and a higher volume than ever before without gaining weight; and feel more energetic doing so.

Of course, many advocacy groups are actively trying to educate people about the wide variety of satisfying vegan foods. In promoting the diet, each person could help prepare potential vegans for the real possibility that they won't feel good if they don't choose some calorie-dense foods.

Less noticeable problems can arise due to misinformation. One can find certain studies that support the idea that meat, eggs, and dairy are the cause of osteoporosis, and that calcium intake is not important. Because the arguments can sound impressive, someone might take these claims as fact. Such a person might conclude that a vegan diet must protect against osteoporosis, and that there is no need for vegans to make sure they are getting plenty of calcium and vitamin D. However, selectively choosing such studies leaves out the majority of research published on the subject. Someone who evaluates more of the research will likely conclude that vegans, like non-vegans, should ensure good sources of calcium and vitamin D on a daily basis.

The other nutritional issues of which vegans should be aware are addressed later in this article.

A Candid Discussion About the Vegan Diet

Few long-term, scientific studies have looked at true vegans. A summary of the research on vegetarians and vegans is included in this article. The research has not overwhelmingly supported the idea that a vegan diet is vastly superior to a diet that includes meat or a lacto-ovo vegetarian diet, and some vegans have found this to contradict what they have always heard. How can this be explained?

Popular vegan literature has sometimes presented studies on groups -- such as lacto-ovo vegetarians, semi-vegetarians, cultures that eat little meat, and people who have a high intake of fruits and vegetables -- as indications of the health status of vegans. Although this can provide some useful information about some aspects of the vegan diet, it cannot substitute for studying actual vegans.

Additionally, certain risk factors, such as cholesterol levels, have been used to make projections about the health of vegans, but these do not necessarily tell the whole story. For example, while vegans' cholesterol levels tend to be low, some vegans' low vitamin B12 status can potentially increase their risk for heart disease and stroke. This is easily solved by ensuring a consistent source of B12.

For a concise explanation of the different types of studies and their pros and cons, please see the section "How are associations between diet and disease established?" in Stephen Walsh's Briefing Paper for the UK Vegan Society, Milk and Breast Cancer.

There are real differences in how people respond to various diets. While many people thrive on a vegan diet, it may not be so easy for others. When someone is committed to reducing animal suffering, there are often solutions to these dilemmas. Affirming everyone's experience is the first step in working with people towards a more humane diet.

I would like to see vegan advocates promote the diet in such a way that we minimize the chances of someone having a bad experience. In so doing, I hope that future, long-term studies on vegans will show us to have even better health than our meat-eating counterparts. Promoting veganism as though there are no nutritional concerns may initially attract more people; but we don't want people merely to go vegan -- we want them to stay vegan.

Acknowledgements: Thanks to Virginia Messina, MPH, RD, Brenda Davis, RD, and Stephen Walsh, PhD for their invaluable help in preparing this article.

Position of the American Dietetic Association and Dietitians of Canada: Vegetarian Diets

In their 2003 Position Paper on vegetarian diets, the American Dietetic Association and Dietitians of Canada state, "Well-planned vegan and other types of vegetarian diets are appropriate for all stages of the life cycle, including during pregnancy, lactation, infancy, childhood, and adolescence. Vegetarian diets offer a number of nutritional benefits, including lower levels of saturated fat, cholesterol, and animal protein as well as higher levels of carbohydrates, fiber, magnesium, potassium, folate, and antioxidants such as vitamins C and E and phytochemicals. Vegetarians have been reported to have lower body mass indices than nonvegetarians, as well as lower rates of death from ischemic heart disease; vegetarians also show lower blood cholesterol levels; lower blood pressure; and lower rates of hypertension, type 2 diabetes, and prostate and colon cancer."³⁰

Summary of Health Benefits of a Vegetarian Diet

Health Benefits of a Vegetarian Diet, a 1999 paper co-authored by two experts on the mortality rates of vegetarians, concludes:

Compared with non-vegetarians, Western vegetarians have a lower mean BMI (by about 1 kg/m²), a lower mean plasma total cholesterol concentration (by about 0.5 mmol/l [19 mg/dl]), and a lower mortality from IHD [ischemic heart disease] (by about 25%). They may also have a lower risk for some other diseases such as diverticular disease, gallstones and appendicitis. No differences in mortality from common cancers have been established. There is no evidence of adverse effects on mortality. Much more information is needed, particularly on other causes of death, osteoporosis, and long-term health in vegans.¹²

U.S. Vegetarians' Health: Latest data from the Adventist Health Study¹

The only major, ongoing study on the general health and mortality of vegetarians in the U.S.
Data collected from 1976-1988
34,192 participants, members of the Seventh-day Adventist church
29% were vegetarian
7-10% of the vegetarians were vegan.

Results were:

	Men		Women
	Vegetarians	Non-vegetarians	Vegetarians	Non-vegetarians
BMI	24.3	26.2	23.7	25.9
Heart disease	38% Lower for Men		No Difference for Women
Overall mortality	Lived 3.21 more yrs		Lived 2.52 more yrs
BMI &45; Body Mass Index. A measure of healthy body weight. Lower than 20 is underweight, while ≥ 25 is overweight.

Compared to the non-vegetarians, vegetarians had about:

1/2 the high blood pressure and diabetes
1/2 the colon cancer
2/3 the rheumatoid arthritis and prostate cancer
Breast, lung, and uterine cancers tended to be lower in vegetarians but could have been due to random chance.

Life expectancies in the Adventist Health Study have recently been published.²⁷ They show that white, non-Hispanic Seventh-day Adventists live longer than other white Californians (7.28 years for men, 4.42 years for women). In fact, according to the researchers, this group of Seventh-day Adventists appears to be the longest-lived, formally studied population in the world (with an average life span of 78.5 years for men, 82.3 for women).

The following variables were shown to increase life expectancy:

vegetarian diet
eating nuts regularly
physical activity
lower body weight
no smoking

The only other variable looked at was hormone replacement therapy for women which possibly contributed to increased life expectancy.²⁷

Current State of Vegan Health

In 1999, data were published from the 4 largest studies (including the Adventist Health Study mentioned above) analyzing vegan mortality rates.² The data compared the risk of dying from various diseases between people with different diets but who had similar lifestyles. The standardized mortality ratios (SMR) in 3 of the studies showed less mortality in these groups than in the population at large (no SMR was calculated for the 4th study). Most of this difference was thought to be due to lower smoking rates in the study groups, but some difference may have been due to a generally healthier diet overall than in the population at large.

Compared to 31,766 people who ate meat ≥ 1/week:

Occasional meat eaters (8,135 people who ate meat < 1/week) had a 20% reduced rate of dying of heart disease and a 10% reduced rate of overall mortality.
Those who ate no meat other than fish (2,375 people) had a 34% reduced rate of dying from heart disease and an 18% reduced rate of overall mortality.
Lacto-ovo vegetarians (23,265 people) had a 38% reduced rate of dying from lung cancer, a 34% reduced rate of dying from heart disease, and a 15% reduced rate of mortality.
Vegans (753 people) had a 26% reduced rate of dying from heart disease (however the difference was not statistically significant, meaning that it could have been due to random chance) and their mortality was the same as the regular meat-eaters.

This data, while not conclusive because of the small number of vegans in the study, indicates that vegans can probably do better in preventing heart disease and possibly other diseases.

Click here for the article The Long Term Health of Western Vegetarians, by Paul Appleby of the European Prospective Investigation into Cancer and Nutrition (EPIC) Study.

Diet and Cancer

It may come as a surprise that vegetarians have not been shown to have lower rates of mortality from cancer. There has not been enough data on vegans to determine their cancer rates. For a recent summary of the evidence regarding diet and cancer, see Diet, Nutrition and the Prevention of Cancer, by Key TJ, Schatzkin A, Willett WC, Allen NE, Spencer EA, Travis RC. of the Cancer Research UK Epidemiology Unit. An earlier version of this paper is The Effect of Diet on Cancer, by Key TJ, Allen NE, Spencer EA, and Travis RC of the Cancer Research UK Epidemiology Unit.

Nutrients That Need Attention in Vegan Diets

All diets must be appropriately planned in order to be healthy. In part because of government requirements intended to prevent nutritional deficiencies in the average American, the food industries in the U.S. fortify a wide variety of products with many different vitamins and minerals. However, since the government and food industries have generally not been concerned with meeting the needs of vegans (although this is changing), vegans must make an effort to ensure adequate intake of certain nutrients.

Jump to Summary of Recommendations for Vegan Adults.

Vitamin B12

There are no reliable, unfortified plant sources of vitamin B12; therefore fortified foods and/or supplements are necessary for the optimal health of vegans. See B12 in Tempeh, Seaweeds, Organic Produce, and Other Plant Foods for more information.

Vitamin B12 protects the nervous system. Without it, permanent damage can result (e.g., blindness, deafness, and dementia). It also keeps the digestive system healthy and reduces the risk of heart disease by lowering homocysteine levels. Early deficiency symptoms sometimes include fatigue, and tingling in the hands or feet.

B12 keeps the digestive system healthy. By lowering homocysteine levels, it also reduces the risk of heart disease, stroke, neural tube defects, and other diseases.

Since 1999, there have been 12 studies comparing the homocysteine levels of vegans, vegetarians, or both, who do not supplement their diet with vitamin B12, to those of non-vegetarians. In every study, the vegans or vegetarians had higher homocysteine levels than the meat-eaters. In all cases, the vegans and vegetarians had homocysteine levels in the range associated with an increased risk of heart disease and stroke. On the other hand, in the one study comparing vegans who were supplementing their diets with vitamin B12 (an average of 5.6 micrograms a day) with non-vegetarians, their homocysteine levels were the same, and well within the healthy range. Details can be read in the section Homocysteine, B12, Vegetarians, and Disease of Vitamin B12: Are You Getting It?

Vegan infants get B12 through breast milk (their mothers must have a consistent B12 intake) or formula.

The Recommended Dietary Allowance (RDA) for vitamin B12 is 2.4 micrograms for adults (abbreviated as µg or mcg).

B12 is stored in the liver. If you have been a typical meat eater for most of your life, your liver should have stored enough B12 to prevent serious deficiency symptoms for a number of years. However, when B12 intake is zero, old B12 stores cannot be relied on to keep homocysteine levels in check.

B12 Recommendations:

In foods, B12 is measured in micrograms (aka "µg" or "mcg"). 1,000 µg = 1 mg.

Step 1. If you have not had a regular source of B12 for some time, buy a bottle of 1,000 µg (or greater) B12 tablets. The following (and many others) are vegan:

Pangea VeganLife B12 Chewable Supplement 1,000 mcg tablets
VegLife sublingual 1,000 mcg lozenges. Sold in stores (website has a store locator).
Freeda Vitamins 500 mcg lozenges
Nature's Bounty sublingual 2500 mcg
Solgar sublingual 1,000 mcg nuggets (cherry flavoring contains beeswax as of 7/19/04 per phone conversation with a reader)

Place 2,000 µg under your tongue until the tablet(s) has dissolved, once a day, for 2 weeks. Then follow the advice under Step #2.

Note: You can break the remaining tablets in half or quarters for Step #2. It's okay to take more than recommended.

Step 2. If you have had a regular source of B12, skip Step 1. One of the following daily recommendations should maximize your B12 status:

1.5 - 2.5 µg, twice a day, from fortified foods or supplements¹
10 - 100 µg, once a day, from a supplement^1,2

Click here for an explanation of how these recommendations were formulated.

Notes for Recommendations

Fortified foods: Amounts listed on a nutrition label are based on 6 µg/day. For example, 25% of the Daily Value = .25 * 6 µg = 1.5 µg.

Do Not Rely On: Any seaweed (e.g., algae, nori, spirulina), brewer's yeast, tempeh, or "living" vitamin supplement that uses plants as a source of B12. Do not rely solely on one type of fortified food such as Red Star Nutritional Yeast.

Vegan Infants: The Institute of Medicine recommends that infants of vegan mothers be supplemented with B12 from birth because their stores at birth and their mother's milk supply may be low.³

Exceptions: People with digestive or malabsorption diseases (such as pernicious anemia), chronic kidney failure, B12 metabolism defects, or cyanide metabolism defects should consult a bona fide health professional.

Cigarette smokers: Should consider a non-cyanocobalamin source of B12. Click here for more information.

Notes for Recommendations for Vegans and Near-Vegans

1. Lower limit based on minimum recommendations in What Every Vegan Should Know about Vitamin B12.
2. In a single dose, B12 absorption drops to 1-1.5% for the amounts above 5 µg.
3. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press; 2000.

See Vitamin B12: Are You Getting It? for more information about B12.

Fats

The following quick summary about fats simply gives basic recommendations. For a more comprehensive discussion see The Challenge of Defining Optimal Fat Intake by Virginia Messina, MPH, RD, and Making Sense of Fats and Oils by Brenda Davis, RD.

Saturated Fats

Many saturated fats raise the risk of heart disease.

Found in high amounts in animal products; also in high amounts in coconut and palm kernel oils.

Saturated fats are stable at high temperatures. If you are going to fry foods at high temperatures, palm oil may be the best vegan choice for its stability. However, deep-fried foods should be limited.

Trans Fats

Found mostly in foods made with hydrogenated or partially hydrogenated oils. Food sources include margarines, shortening, commercial frying fats, crackers, cookies, and other snacks. The ingredients will list whether these foods are made with hydrogenated oils. Butter and animal fat can also contain trans-fats from bacterial fermentation.³³

The consensus among nutritional professionals is that trans fats increase the risk of heart disease and many other diseases.

Two vegan margarines that do not contain hydrogenated oils are Soy Garden and Earth Balance, available at many natural foods stores.

Monounsaturated Fats (MUFA)

Also known as omega-9 fats, n-9, or oleic acid.

Improve cholesterol levels.

Abundant in olive oil, canola oil, high oleic sunflower oil, hazelnut oil, high-oleic safflower oil, and almond oil.

Olive may be the best oil with which to fry foods at moderate temperatures because it is not as refined as other oils, making it a reliable source of vitamin E and possibly other healthy compounds. It has stood the test of time, being used as a primary oil in the Mediterranean diet. This diet has been shown to have many health benefits. I recommend cooking with olive oil whenever possible. If you do not like the taste of olive oil in some fried foodsdishes, I would suggesttry other oils made of high MUFA. See chart.

Avocados and many nuts (almonds, cashews, filberts/ (hazelnuts), macadeamias, peanuts, and pecans) are high in MUFA. Because nuts are high in nutrients and other protective compounds, adults can benefit from eating them on a daily basis.

Polyunsaturated Fats (PUFA)

There are two main families: omega-3s and omega-6s.

Omega-6s (n-6)

Building blocks for hormones that increase inflammation and blood clotting.
Linoleic acid is the most prevalent omega-6 in plant foods.
Prevalent in corn, sunflower, "vegetable," soy, and safflower oils.

Most vegans get too much Omega-6 fat, and should limit these oils, especially in cooking.³⁸

Omega-3s (n-3)

There are 3 important n-3 fatty acids:

alpha-Linolenic acid (LNA) - found mainly in flaxseeds and oil, hemp seeds and oil, walnuts and oil, canola oil, soybeans and oil. Also found in leafy green vegetables and other plant foods, but not in large enough amounts to contribute significantly.

LNA reduces blood clotting, improves artery flexibility, and may also reduce heart arrhythmias. LNA shows a strong association with reduced cardiovascular mortality rates, including those from heart attack and stroke.
Eicosapentaenoic acid (EPA) - found mainly in fatty fish. Also in irish moss and wakame, but the ratio of iodine to EPA is much too high to make these foods a recommended source.

EPA serves as a precursor for eicosanoids (hormone-like substances that act on local tissues) which reduce inflammation, blood clotting, and cholesterol.
Docosahexaenoic acid (DHA) - found mainly in fatty fish and seaweed.
Major structural component of the gray matter of the brain, the retina of the eye, and cell membranes.
Low levels of DHA have been associated with depression.

For some of its benefits, LNA must be converted to EPA which in turn must be converted to eicosanoids or DHA. DHA can also be retroconverted into EPA at a rate of about 10%.³⁶ Although there is no clear evidence that vegans require supplements of DHA or EPA, vegan supplements of DHA are also available:

NuTru's O-Mega-Zen3
In vegetable-based gelcaps. 300 mg of DHA per capsule.
Available from Pangea and Vegan Essentials.
Genestra Neurogen DHA
Marketed by Seroyal out of Toronto Ontario. Call 800-263-5861. 100 mg DHA per capsule.
Neuromins© DHA is available at most health food stores, but it comes in gelatin capsules.

Notes About Flax & Hemp

Flaxseeds are the most concentrated source of LNA. Cooking flaxseed oil damages the LNA, but it can be put on warm food such as toast. Flaxseed oil should be kept in the refrigerator.
One teaspoon of flaxseed oil contains 2.5 g of LNA.
One tablespoon of flaxseeds contains 2.1 g of LNA.
- If flaxseeds are not ground, there is a chance they will not be digested. They can be ground in a blender (works best with a large amount) or coffee grinder, and then stored in the freezer. Ground flaxseeds can be sprinkled on cereal or used in baked goods.
Hemp seed oil is also a good source but not available everywhere.

PUFA Recommendations

Many vegans do not get enough n-3 fat.¹⁵ This can result in higher blood clotting rates, a risk for heart attack and stroke.

A panel of experts recently recommended an n-3 intake for nonvegetarians of about 1.3% of calories.³⁷ They recommended an additional 300 mg/d of DHA for pregnant and lactating nonvegetarians. Limiting n-6 intake and making intake of LNA 1.5% of calories will enhance conversion of LNA to EPA and DHA; however, it can sometimes take a few months of following these recommendations to build up DHA. Based on the RDA for caloric intake (and subtracting .5% of kcal for usual intake without any supplementation), the following amounts of LNA should be added to the diet:

age (years)	LNA (g/day)	flaxseed oil (rounded teaspoons)
0.5-6	.9 - 2.0	.5
> 7	2.2 - 3.3	1

Pregnant^A
2nd Trimester	An extra .3	An extra .5
3rd Trimester	An extra .3	An extra .5
Lactating^A	extra .6	extra .5
A &45; Pregnant and lactating women should consider replacing the extra .5 teaspoon of flaxseed oil with 300 mg (.3 g) of DHA because infants have more difficulty converting n-3s.

Limit n-6 Fats

Limiting n-6 intake is important for maximizing the conversion of n-3s into EPA and DHA. You should aim for an n-6 to n-3 ratio of 4:1 or less. The following sources of n-3s are followed by their approximate ratio of n-6 to n-3:

n-3 source	approx. n-6:n-3 ratio
flaxseeds/flaxseed oil	1:4
canola oil	2:1
english walnuts	4:1 - 5:1
walnut oil	5:1
soybean oil	7.5:1
black walnuts	10:1

Only the top 2 foods (flaxseeds and canola oil) fall below the recommended ratio of n-6:n-3. This means that other foods will not decrease the ratio to 4:1, though walnuts will not harm the ratio much and do provide omega-3s.

While flaxseed oil goes a long way in correcting the imbalance in a typical vegan diet, you should only take the recommended amounts. If you prefer oils on foods such as bread, I recommend raw olive or raw canola oil to minimize your n-6:n-3 ratio as well as for other benefits.

English walnuts are the typical walnuts found in most grocery stores.

Diabetes
People with diabetes do not efficiently convert LNA to EPA and DHA. Diabetic vegans should replace .3 grams of LNA with 300 mg of DHA per day.

Pre-Term Infants
Parents with prematurely-born infants should contact a health professional about supplementing their diets with essential fatty acids.

Calcium

Recent, small studies have shown vegans to have the same or slightly worse bone mineral density as non-vegans.^{5, 6, 7, 8, 9}

Factors that can prevent osteoporosis:

Weight-bearing exercise throughout one's lifetime is one of the most important.
Adequate calcium, vitamin D, vitamin K, protein, potassium, magnesium, and boron intakes.
Adequate estrogen levels (for women)

Factors that can contribute to osteoporosis:

High sodium and caffeine intake
Smoking
Excessive amounts of, or too little, protein

Plant foods that provide calcium offer other things that are good for bones: vitamin K in leafy greens; and vitamin C, potassium, and magnesium in fortified orange juice. Leafy greens also have folate which is good for the heart. Beans, nuts, leafy green vegetables, and non-citrus fruits are good sources of boron.¹⁰

The calcium in kale, broccoli, collard greens, and soymilk is absorbed about the same percentage as that in cows' milk.
The calcium in spinach, Swiss chard, and beet greens is not well absorbed, due to their high content of oxalates, which bind calcium.
Many non-dairy milks are now fortified with calcium, vitamin D, and/or vitamin B-12. Many orange juices and other juices are fortified with calcium.
Make sure you shake calcium fortified non-dairy milks before pouring as the calcium can settle on the bottom.

Calcium supplements can inhibit iron absorption if taken eaten at the same time.²³

The Daily Value for calcium on food labels is 1,000 mg. Therefore, if a food label says it has 25% of the daily value, it means it has 250 mg of calcium per serving.

Recommended daily intakes for calcium:

Age	mg	Upper Limit*
1 - 3	500	2500
4 - 8	800	2500
9 - 18	1300	2500
19 - 50	1000	2500
>50	1200	2500
*Do not exceed the upper limit.

Plant foods high in calcium:

Food	Serving	Ca (mg)
cow's milk (for comparison)	1 C	300
soymilk, fortified^b	1 C	200-300
tofu (if 'calcium-set')	1/2 C	120-300
figs, dried	5 T	258
orange juice, fortified^b	1 C	250
blackstrap molasses	1 T	187
collard greens^a	1/2 C	178
sesame seeds	2 T	176
veg baked bean	1 C	128
navy beans	1 C	128
kale^a	1/2 C	90
broccoli^a	1/2 C	50
almonds	2 T	50
a - Cooked b - Read the label for calcium amounts.

Vitamin D

Regulates calcium absorption and excretion, especially when calcium intake is low.
The only significant, natural sources of vitamin D in foods are fatty fish (e.g. cod liver oil), eggs (if chickens have been fed vitamin D), and possibly some wild mushrooms.¹⁸ Most Americans get vitamin D through fortified milk and fortified margarine.
Vitamin D can be made by the action of sunlight (UV rays) on skin. Light-skinned, non-elderly adults exposing their hands and face to sunlight during the summer for 10-15 minutes, 2-3 times/week should get enough vitamin D from sunlight. Extra amounts can be stored for during the winter, however, there is some evidence that these stores are not enough for those living in northern climates. See Vitamin D: The Forgotten Nutrient.
Vegans who do not get much sunlight exposure should supplement with vitamin D, especially during the winter or cloudy months.
Elderly people may need up to 4 times,¹⁸ and dark-skinned people may need up to 6 times, the amount of sun listed above in order to meet vitamin D needs through sunshine alone. Thus, it is prudent to take a modest vitamin D supplement or use fortified foods.
Breast milk is low in vitamin D and varies according to the mother's intake/sun exposure. According to some experts, dark-skinned, breast-fed babies should be given vitamin D supplements.¹⁸
Vitamin D is not synthesized during the winter in northern climates.¹⁰

Types of vitamin D:

Vitamin D3 - cholecalciferol; is derived from animal foods or made by the action of ultraviolet light on the skin.

Vitamin D2 - ergocalciferol; a plant chemical that has vitamin D activity in humans, but not as much activity as D3; therefore vegetarians who rely on D2 may need slightly higher intakes.¹⁸

One small study found an increase in lumbar spine (lower back) bone density in 4 out of 5 vegans in Finland (a northern country where sunlight does not activate vitamin D during the winter) who took 5 mcg/day of vitamin D2 for 11 months.⁴
The Daily Value for vitamin D is 10 mcg (400 IU). Therefore, if a food label says it has 25% of the daily value, it means it has 2.5 mcg (100 IU) per serving.

Dietary Reference Intake (DRI) for vitamin D
Age (yrs)	DRI mcg(b) (IU)	Upper Limit^A mcg^B (IU)
< 1	5 (200)	25 (1000)
1-50 yrs old (incl. pregnancy)	5 (200)	50 (2000)
51-70 yrs	10 (400)	50 (2000)
Over 70	15 (600)	50 (2000)
A - Do not exceed the upper limit. B - mcg = microgram = µg

Sources of Vitamin D:

Typical fortified soy, almond, or rice milk: 2-3 mcg (80-120 IU) per Cup

Vitamin D-only Supplements:

Country Life ergocalciferol: 25 mcg (1000 IU) D2 per tablet (can break in half)
Sold in many health food stores.
Thompson ergocalciferol: 10 mcg (400 IU) D₂ per tablet
Can order at Herbal Hut.
Multivitamins containing vitamin D₂.

Iodine

Needed for healthy thyroid function which regulates metabolism. Both too much, and too little, iodine can result in abnormal thyroid metabolism.
Studies have shown that vegans in Europe (where salt is not iodized) who do not supplement (as well as those who oversupplement) have indications of abnormal thyroid function.^19,20
Iodine is found in produce grown in some parts of the country, but in very small amounts. It does not appear to as much of a problem for U.S. vegans as it is for European vegans,^19,20 whose food supply contains less iodine. North American vegans should take a modest iodine supplement on a regular basis to ensure they are meeting requirements because it's very hard to predict how much is in any given person's food supply. 75-100 mcg every few days should be ample.
Avoid intakes in excess of Upper Limit.

Dietary Reference Intake (DRI) for Iodine
Age (yrs)	RDA (mcg^B)	Upper limit^A (mcg^B)
1 - 3	90	200
4 - 8	90	300
9 - 13	120	600
14-18	150	900
> 18	150	1100
pregnant
≤ 18	220	900
> 18	220	1100
lactating
≤ 18	290	900
> 18	290	1100
A - Do not exceed the upper limit. B - mcg = microgram = µg

Vegan iodine supplements can be found in most grocery or natural food stores. Most vegan multivitamins also contain iodine.

More details on iodine from the UK Vegan Society. An excerpt:

...Iodine deficiency during pregnancy and early infancy can result in cretinism (irreversible mental retardation and severe motor impairments).... Hypothyroidism can manifest as low energy levels, dry or scaly or yellowish skin, tingling and numbness in extremities, weight gain, forgetfulness, personality changes, depression, anaemia, and prolonged and heavy periods in women.... Hypothyroidism can also cause carpal tunnel syndrome and Raynaud's phenomenon [episodes of blood flow loss to the fingers, toes, ears, and nose]. Hypothyroidism can lead to significant increases in cholesterol levels and homocysteine levels is implicated in about 10% of cases of high cholesterol levels. Correcting hypothyroidism can lead to a 30% drop in cholesterol and homocysteine levels.

Protein

It was once believed that vegetarians (and vegans) needed to combine protein sources at each meal to get "complete protein." Now we know that protein combining at each meal is not necessary.

In their Position Paper on Vegetarian Diets, The American Dietetic Association states:

"Plant protein can meet requirements when a variety of plant foods is consumed and energy needs are met. Research indicates that an assortment of plant foods eaten over the course of a day can provide all essential amino acids and ensure adequate nitrogen retention and use in healthy adults, thus complementary proteins do not need to be consumed at the same meal."

Experts recommend that adult vegans eat .4 g of protein per day for every pound of healthy body weight.²² Recommendations for younger vegans are:²⁶

Protein Recommendations for Young Vegans
Age (yrs)	Females (grams/day)	Males (grams/day)
1 - 2	18-19	18-19
2 - 3	18-21	18-21
4 - 6	26-28	26-28
7 - 10	31-34	31-34
11 - 14	51-55	50-54
15 - 18	50-55	66-73

The plant foods highest in protein are legumes (beans, peanuts, soyfoods such as tofu) and nuts, but grains and vegetables also contribute significant amounts.

Protein Content of Common Vegan Foods
	Serving	Protein (g)
Naturade soy protein powder	1/3 Cup	23 g
Naturade soy-free protein powder	1/3 Cup	22 g
Seitan	3 oz	22.5
Tofu	1/2 Cup	10 - 20
Veggie dog/burger	1	6 - 18
Tempeh*	3 oz	15.5
Soybeans*	1/2 Cup	14.3
Texturized soy protein	1/2 Cup	11
Soymilk	1 Cup	5 - 10
Lentils*	1/2 Cup	8.9
Peanut butter	2 Tablespoons	8
Chickpeas*	1/2 Cup	7.5
Refried beans*	1/2 Cup	6.9
Sunflower seeds	1/4 Cup	6.2
Oatmeal*	1 Cup, instant	5.9
Brown rice*	1 Cup	5
Broccoli*	1 Cup chopped	4.6
Potato, baked	1 medium	4.5
Walnuts	1/2 oz (7 halves)	4.3
White rice*	1 Cup	4.1
Almonds	1/2 oz (12 kernels)	3
Kale*	1 Cup chopped	2.5
Taco shell	1 medium	1
Carrot	1 med	0.6
*Cooked

Click here to check the USDA National Nutrient Database for the content of protein or other nutrients in foods.

Vegans Might not Meet Protein Needs If...

Vegans might not meet their protein needs, resulting in a loss of muscle mass and/or reduced immunity, if:

1. Food intake does not meet energy needs such as in cases of anorexia nervosa, depression, poverty, lack of appetite due to illness,³ or dieting.

2. Higher-protein plant foods are not included in sufficient amounts. This can happen when:

Most food eaten is junk food such as French fries, soda, etc.
Protein is believed to be unimportant and/or higher protein foods are avoided (such as in some fruitarian or raw food diets).
Beans are avoided.³ (Other high-protein foods should be used.)

Vegan athletes interested in how much protein they need should see Vegetarian Diet for Exercise and Athletic Training and Performing: An Update by D. Enette Larson, MS, RD, LD.¹¹

For more information on the amino acid RDAs and content of plant foods, see Where Do You Get Your Protein?

Non-Protein Amino Acids

Taurine and Carnitine

Taurine and carnitine are non-essential amino acids. They are found primarily in animal products. If you are eating enough protein, your body should make what you need. If you go an extended period of time without eating enough protein, or if you have a metabolic problem, you might benefit from a period of supplementation. In such cases, it is prudent to contact a health professional. There is no reason for most vegans to be concerned.

Non-vegetarians typically eat 40 - 70 mg of taurine per day⁴¹ and 100 - 300 mg of carnitine per day.⁴² Country Life's Vegetarian Support multi-vitamin contains 25 mg of taurine per tablet.

A carnitine metabolic problem has been linked to migraines. If you are a vegan who started getting migraines after becoming vegan, you might consider talking to your health professional about carnitine supplementation.

Creatine

Creatine is a combination of the amino acids glycine, arginine, and parts of methionine. It is used in skeletal muscle for quick energy. It is not found in plant foods.

Because vegetarians do not eat any creatine (the average intake for a meat-eater is 2 g/day¹¹), it is thought that vegetarian athletes might benefit from supplementation. Manufacturers claim that creatine supplements are synthesized from non-animal products.¹¹ Before taking creatine, vegetarian athletes should read up on the subject such as in the article by Larson¹¹ and the section on creatine in Becoming Vegan³.

Iron

Also see, What should I do if my doctor tells me to eat meat because I have iron deficiency anemia?

Iron-deficiency anemia is probably one of the most inaccurately self-diagnosed illnesses. Only a medical doctor can diagnose it properly and people who think they may be suffering from it should see a doctor.

Iron-deficiency symptoms include pale skin, brittle fingernails, fatigue, weakness, difficulty breathing upon exertion, inadequate temperature regulation, loss of appetite, and apathy.

Iron in vegan diets is a somewhat controversial topic for a number of reasons:

Vegetarians' ferritin (the storage form of iron) levels are often lower than non-vegetarians, but they are no more likely to have iron-deficiency anemia in studies done to date.
Low iron stores are associated with higher glucose tolerance and therefore could prevent diabetes.
High blood levels of iron have been linked to heart disease and cancer.
- After reviewing the evidence on iron intake and heart disease, the Food and Nutrition Board of the Institute of Medicine says, "This body of evidence does not provide convincing support for a causal relationship between the level of dietary iron intake and the risk for CHD [coronary heart disease]."³² There is a possible link for heart disease in people who have ferritin concentrations greater than 200 mcg/l.
- Studies on iron levels in vegans show that vegans' ferritin levels are rarely above 100 mcg/l. The association with cancer appears stronger.
Vegans normally have as high, or higher, iron intakes as non-vegetarians.
- However, plant iron is generally not absorbed as well as iron from meat.
- Vitamin C significantly aids in iron absorption (the iron and vitamin C must be eaten at the same meal) and vegans tend to have high intakes of vitamin C.
  - In one study, vegetarian children with iron deficiency anemia were given 100 mg of vitamin C at both lunch and dinner for 60 days. They saw a drastic improvement in their anemia with most making a full recovery.³⁹

Calcium supplements, coffee, and tea inhibit iron absorption if taken at the same time, so avoid them at meals in which you are trying to increase iron absorption.²³

Hemochromatosis is a disease of increased iron absorption. Its most serious, homozygous form occurs in about 1 in 100 blacks and 1 in 200 nonblacks. Its less serious, heterozygous form occurs in 30% of blacks and 12% of nonblacks.³³ Most affected people do not know they have the disease.³³ People with hemochromatosis are at risk for cirrhosis,³³ liver cancer,³² and other diseases. Alcoholic cirrhosis, other liver diseases, iron-loading abnormalities, and other rare diseases can also cause iron overload.³² Thus, before someone actively tries to increase their iron absorption, they should have their ferritin levels checked to make sure they do not have one of these diseases.

Because of blood loss, menstruating vegan women do not need their serum ferritin levels checked before taking steps to increase iron absorption.

The Upper Limit for iron is set to prevent gastrointestinal distress and not to prevent possible chronic diseases from iron overload.³²

Amounts listed on a nutrition label are based on 18 mg/day.
For example, 25% of the Daily Value = .25 * 18 mg = 4.5 mg.

The new U.S. RDA's for iron distinguished between vegetarians and nonvegetarians. The RDA for vegetarians was determined by increasing the regular RDA by 1.8 times.²¹ However, this is very controversial because the recommendations were not based on studies of vegetarians. Most vegan dietitians do not think it is necessary to get this much iron. For that reason, the RDA's for non-vegetarians are listed here.

Recommended Dietary Allowance for Iron
Age (years)	RDA (mg)	Upper limit^A (mg)
.5 - 1	11	40
1 - 3	7	40
4 - 8	10	40
9 - 13	8	40
boys, 14-18	11	45
girls, 14-18	15	45
breastfeeding	18	45
men > 19	8	45
women 19-50	18	45
women > 50	8	45
pregnant women	27	45
breastfeeding	10	45
A - Do not exceed the upper limit. Those who engage in regular, intense exercise may need an additional 30%.²¹

Iron Content of Common Foods
	Serving	mg
fortified cereals	1/2 C	varies
soybeans^A	1/2 C	4.4
blackstrap molasses	1 T	3.3
pumpkin seeds	2 T	2.5
chickpeas^A	1/2 C	2.4
pinto beans^A	1/2 C	2.2
apricots, dried	1/4 C	1.5
spinach^A	1/2 C	1.5
raisins	1/4 C	1.1
A &45; Cooked

Recommendations for Iron

You probably do not need to worry about iron if you are otherwise healthy and eat a varied vegan diet. If you suspect an iron deficiency, see a doctor. If your doctor thinks your iron stores are too low, eating meat (which is unnecessary) or taking an iron supplement may be suggested. Taking a 100 mg vitamin C tablet with 2 meals a day for 60 days should improve the anemia.

Zinc

Zinc is not found in large amounts in plant foods, but vegetarians tend to have adequate zinc status.
Symptoms of zinc deficiency include poor growth and delayed sexual maturation in children, poor wound healing, hair loss, impaired immune function, and dermatitis (especially around body orifices).²³
Sources: legumes, nuts, corn, peas, cashews, peanuts, peanut butter, pumpkin seeds, and sunflower seeds; cereals are often fortified with zinc.
Protein increases zinc absorption. Because of this, foods high in protein and zinc, such as legumes and nuts, are good choices.²⁶
The leavening of bread (most bread is leavened) and fermenting of soyfoods (tempeh and miso) also enhances zinc absorption.²⁶

Selenium

Selenium intake is more related to the selenium content of the soil than to dietary pattern. U.S. and Canadian soil appears to be adequate in selenium. Studies of vegetarians and vegans in the U.S. have shown them to have adequate intakes. Selenium is found in many foods, but in higher amounts in Brazil nuts, whole grains (whole-wheat bread, oatmeal, barley), white rice, and beans.²²

Vitamin A

Pre-formed vitamin A exists only in animal products. However, there are about 50 carotenoids that the body can convert into vitamin A; the most common is beta-carotene. The vitamin A content of foods is now stated as retinol activity equivalents (RAE). The RDA of 900 RAE for men and 700 RAE for women, can be met with:

Food	Amount	RAE
Carrot	1 Medium	1012
Baked Sweet Potato	1 Medium	1244
Cantaloupe	2/3	1290
RAE - Retinal activity equivalents

Other sources include kale, mango, spinach, butternut squash, and various greens.

Other Nutrients & Multivitamins

Some people may have specific problems absorbing or utilizing certain nutrients (regardless of their diet). There are certain nutrients that are normally provided adequately by a varied vegan diet, but can be low in some vegans' diets. Riboflavin (vitamin B2) and pyridoxine (vitamin B6) are two such nutrients. For example, while most vegans have no problem with vitamin B6, numerous members of one vegan family showed symptoms of vitamin B6 deficiency.²⁴

Symptoms of vitamin B2 deficiency are sores outside of the lips and in the corners of the mouth, swollen tongue and mouth cavity, and dermatitis.²³ Vitamin B2 is found in a wide variety of plant foods in small amounts, including avocados, mushrooms, almonds, leafy green vegetables, and soybeans.²⁶
Symptoms of B6 deficiency include sleepiness, fatigue, sores in the sides of the mouth, and a swollen tongue.²³ Bananas, navy beans, and walnuts are all good sources of vitamin B6.²³
Cereals are often fortified with iron, zinc, and B vitamins.
Some researchers suggest taking a modest multivitamin supplement regardless of your diet. I recommend one that is about 25-100% of the RDA. Tablets can be broken in half.

Pregnancy

Click here (opens in new window) to read the article, Vegan Pregnancy, by Reed Mangels, PhD, RD. from the Jan/Feb 1997 issue of The Vegetarian Journal.

Infants and Children

Infants

The American Dietetic Association and the American Academy of Pediatrics agree that well-planned vegan diets can satisfy nutrient needs and normal growth of infants.²⁵ For more information on the needs of vegan infants, please see Feeding Vegan Kids by Reed Mangels, PhD, RD and Becoming Vegan.

Soy Formulas

If you need to feed your baby formula, soy formulas are available. Unfortunately, they all contain vitamin D3 which usually comes from sheep's wool or fish. As of 2001, the following brands were vegan except for the vitamin D3:

Vegan parents should not try to make their own infant formulas as this often leads to poor child development. Instead, we recommend commercial infant formulas, even though they are not 100% vegan. (More thoughts on the subject of trying to be 100% vegan.)

Click here for more information on vegan infants from the Vegetarian Resource Group.

Are infant soy formulas safe?

Infant soy formulas have been around for many years and used without apparent problems. However, there has recently been a concern that the isoflavones in soy could be harmful for infants.

Click here for an abstract of the only long-term study comparing infants receiving cow's milk formula to infants receiving soy formula.

Click here for an abstract of a more recent review of the subject.

Click here for an article about a recent, ongoing study of soy infant formulas conducted by the Agricultural Research Service of the USDA. A summary of the article is that there have been no observed negative effects of soy formulas in humans but some animal research has raised concerns that soy formulas may cause infants to metabolize drugs abnormally fast. While this has not yet been directly studied in human infants, it seems that researchers looking at other aspects of soy formulas' effects on infants would have observed manifestations of abnormally fast drug metabolism if it were a common or serious problem.

Breast-feeding is the best option when possible. Although, more research is desirable, it appears that soy formulas are generally safe.

Fiber and Children

The American Academy of Pediatrics recommends that children eat no more than .23 g of fiber per pound of body weight per day. Vegan children can easily exceed this limit. They might come closer to recommendations by eating half of their servings of grains as refined grains (e.g., white pasta, white rice, white bread).²⁶

Vegan children who do not eat much because they get full easily may benefit from eating some low-fiber foods such as refined grains, peeled fruits and vegetables, and added oils.²⁶ Nut and nut butters can also increase their calorie and protein intake. For younger children, be sure to chop or grind nuts well enough to prevent choking.

For more information, check out Raising Vegetarian Children by Joanne Stepaniak, MS ED and Vesanto Melina, MS, RD.

Benefits of Selected Vegan Foods

Beans and Nuts

In addition to being excellent sources of protein, beans and nuts have many other benefits such as vitamins, minerals, fiber, and other chemicals that may prevent cancer and heart disease.^28,29 Nuts also contain monounsaturated fats which are healthy for the heart. In one study, eating nuts (including peanuts³⁴) 5 or more times per week reduced heart disease by about 50%!¹

Fruit and Vegetables

High fruit and vegetable consumption has been associated with a reduced risk for cardiovascular disease, several common cancers, and other chronic diseases (such as macular degeneration and cataracts).

Whole Grains

Whole-grain consumption has been associated with a reduced risk for heart disease, diabetes, hypertension, and stomach and colon cancer. Whole grains include brown rice, whole-wheat bread, barley, oatmeal, corn, quinoa, and millet.

Summary of Daily Suggestions for Vegan Adults

	Recommended Daily Intakes^A
Vitamin B12	3-100 mcg (µg)
Omega-3 fats	2.2 - 3.3 g^B
Calcium	1000 - 1200 mg
Vitamin D	5-15 mcg (200-600 IU)
Iodine	75 - 150 mcg every few days
General Health	Plenty of green and yellow vegetables, other vegetables, fruits, nuts, legumes, and whole grains.
A - See different sections for needs of other age groups. B - Most easily obtained through 1-2 teaspoons of flaxseed oil.

Vegan Multivitamins

	B12 mcg^A	Iodine mcg	D2 mcg (IU)	per bottle	Approx. Cost
Country Life in health food stores Vegetarian Support	125	none	2.5 (100)	60 T	$12
Dr. Joel Fuhrman's Gentle Care Formula	5	25	10 (400)	180 T	$25
Freeda Freedavite Tiny Tablet Multi-Vitamin & Mineral^B	6	75	10 (400)	250 T	$13 + $5 s/h
Pangea 800-340-1200 VeganLife Multivitamin	16.7	38	.4 (16.7)	120 T	$19 + $5 s/h
Prescription2000 916-483-1085 Daily Multivitamin/Mineral	75	38	2.5 (100)	120 C	$18 + $4.25 s/h
VegLife in health food stores Vegan One Multiple	100	150	10 (400)	60t	$13
A - microgram = mcg = µg B - Company says their vitamin A (palmitate) and D are from non-animal sources. C - Numbers are calculated per tablet (T) or capsule (C).

For more a more extensive list of vegan multivitamins and a list of other nutrients they include, click here.

Resources

See VeganHealth.org's Table of Contents.

Newsletters

Vegetarian Nutrition & Health Letter
1711 Nichol Hall
Loma Linda University
Loma Linda, CA 92350
1-888-558-8703
1 year, 10 issues subscription for $24.

Footnotes

1. Fraser GE. Associations between diet and cancer, ischemic heart disease, and all-cause mortality in non-Hispanic white California Seventh-day Adventists. Am J Clin Nutr. 1999 Sep;70(3 Suppl):532S-538S.

2. Key TJ, Fraser GE, Thorogood M, Appleby PN, Beral V, Reeves G, Burr ML, Chang-Claude J, Frentzel-Beyme R, Kuzma JW, Mann J, McPherson K. Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. Am J Clin Nutr. 1999 Sep;70(3 Suppl):516S-524S.

3. Davis B, Melina V. Becoming Vegan: Summertown, TN: Book Publishing Co; 2000.

4. Outila TA, Lamberg-Allardt CJ. Ergocalciferol supplementation may positively affect lumbar spine bone mineral density of vegans. J Am Diet Assoc 2000 Jun;100(6):629.

5. Barr SI, Prior JC, Janelle KC, Lentle BC. Spinal bone mineral density in premenopausal vegetarian and nonvegetarian women: cross-sectional and prospective comparisons. J Am Diet Assoc 1998 Jul;98(7):760-5.

6. Hu JF, Zhao XH, Jia JB, Parpia B, Campbell TC. Dietary calcium and bone density among middle-aged and elderly women in China. Am J Clin Nutr 1993 Aug;58(2):219-27.

7. Janelle KC, Barr SI. Nutrient intakes and eating behavior scores of vegetarian and nonvegetarian women. J Am Diet Assoc 1995 Feb;95(2):180-6, 189, quiz 187-8.

8. Lau EM, Kwok T, Woo J, Ho SC. Bone mineral density in Chinese elderly female vegetarians, vegans, lacto-vegetarians and omnivores. Eur J Clin Nutr 1998 Jan;52(1):60-4.

9. Parsons TJ, van Dusseldorp M, van der Vliet M, van de Werken K, Schaafsma G, van Staveren WA. Reduced bone mass in Dutch adolescents fed a macrobiotic diet in early life. J Bone Miner Res 1997 Sep;12(9):1486-94.

10. Wardlaw GM. Perspectives in Nutrition, 4(th) Ed. Boston, MA: McGraw-Hill; 1999.

11. Vegetarian Diet for Exercise and Athletic Training and Performing: An Update, by D. Enette Larson, MS, RD, LD.

12. Key TJ, Davey GK, Appleby PN. Health benefits of a vegetarian diet. Proc Nutr Soc. 1999 May;58(2):271-5.

15. Mezzano D, Munoz X, Martinez C, Cuevas A, Panes O, Aranda E, Guasch V, Strobel P, Munoz B, Rodriguez S, Pereira J, Leighton F. Vegetarians and cardiovascular risk factors: hemostasis, inflammatory markers and plasma homocysteine. Thromb Haemost 1999 Jun;81(6):913-7

18. Vitamin D. Vegetarian Nutrition & Health Letter Loma Linda University School of Public Health. 2001;4(5):1-5.

19. Appleby PN, Thorogood M, Mann JI, Key TJ. The Oxford vegetarian study: an overview. Am J Clin Nutr 1999 Sep;70(3 Suppl):525S-531S.

20. Lightowler HJ, Davies GJ. Iodine intake and iodine deficiency in vegans as assessed by the duplicate-portion technique and urinary iodine excretion. Br J Nutr 1998 Dec;80(6):529-35I.

Summary

Contents

Introduction