Vegan diets are great, but there are several essential nutrients you need to know about and in some cases supplement. A 2009 article in the American Journal of Clinical Nutrition 1 did a nice overview of this, and I’ve summarized the results below:
Vitamin B-12 维生素B12
Recommendation: 2.4 micrograms (mcg) / d 2
The prevalence of Vitamin B12 deficiency is higher in vegans than in omnivores. Since B12 is only reliably found in animal products, the article recommends supplementation or eating fortified foods to avoid this. Read more about the necessity of B12 and where to get it here.
Vitamin D 维生素D
Recommendation: 600-800IU/day3 Vitamin D3 (safe levels up to 4000IU per day for adults)
建议：600－800IU (International Unit“IU”是国际单位）的维生素D3 (4000IU一下是安全的）
Vegans tend to be deficient in Vitamin D, with just 1/4 the intake of omnivores on average. But they are not alone, especially in places where people don’t get adequate sun exposure (~94% of all middle-aged and older adults in Beijing and Shanghai are Vitamin D deficient). 4 If you don’t want to stand outside in the winter or eat fish, supplements are essential for long-term health. Buy Vitamin D3, as D2 is not as bioavailable. D3 is produced from either fish or lambs wool derivative called lanolin. I consider the later to be in the vegan spirit, it’s an “animal product” but you don’t have to slaughter sheep to harvest the wool. I avoid D3 made from fish products if possible.
纯素食者易于缺失维生素D, 平均摄取量是不吃素的人的25％。 但是，他们不是唯一缺失维生素D的人群。生活在缺乏足够阳光的地方也很容易缺失维生素D, 因为人们只能通过直接晒太阳或吃鱼来吸收维生素D。在北京和上海，94％的中老年人都缺少维生素D! 如果你不能常常晒到太阳或者不常常吃鱼的话，那么为了你的长期健康补充维生素D是必需的。
维生素D 有两种：D3和D2。人体吸收D3的效果比D2好，所以买维生素D时最好买D3。 另外，D3来自于鱼或羊毛脂。我自己尽可能不买鱼制品。羊毛脂具体来说也不算纯素因为是动物产品。但是因为不用杀羊提取羊毛脂，我自己觉得是算素的。
Vitamin D really is critical when it comes to immunity, bone health, and cancer prevention. You can read more about the benefits and recommended intakes here from Dr. Saint-Cyr, family practitioner based in Beijing.
Recommendation: 800mg/d for women 17-50 and men up to 71, 1,000mg/d for women above 50 and men above 71, 1,300mg/d for adolescents 5
Vegans tend to fall short on the recommended intake of calcium. In vegans with low calcium intake, a higher rate of fractures and lower bone mineral density compared to non-vegans has been reported. However, for vegans consuming at least 525 mg calcium/d, this difference disappears. Vitamin D is also essential for bone health, so vegans who get the amount of Vitamin D and calcium recommended by the Institute of Medicine should have no issue with bone density.
Vegan foods containing calcium are abundant. For example:
I take 400mg/d in supplement form just in case. You can take calcium carbonate or calcium citrate. Calcium carbonate should be taken with meals, and avoid taking more than 500 mg at a time for optimal absorption. 7
Non-vegans also take note, the median intake of calcium for many Americans, especially girls 9-18, women 51-70, and men and women over 70, tend to fall below the recommended amount. 8 9 In China a national survey reported less than 5% of people reached the adequate intake for calcium. 10
Omega-3: DHA and EPA 脂肪酸DHA/EPA
建议：每天0.5-1.8 克 脂肪酸 EPA＋DHA， 每天1.1-1.6 克 脂肪酸 ALA
Vegans tend to have low blood concentrations of EPA and DHA, as these two omega-3 fatty acids are only found in seafood, eggs, and certain kinds of seaweed and kelp.
Most nutritional powders and supplements advertising Omega-3 fatty acids only contain ALA, which converts poorly to EPA and DHA in the body. There are vegan supplements for DHA/EPA available made from algae, but they tend to be slightly more expensive than the more common EPA/DHA supplements made from fish oil.
The article advises a diet rich in ALA as well as a DHA supplement.
DHA is generally considered safe, although in some studies it has raised the overall level of LDL cholesterol in subjects. I would imagine the benefits outweigh any dangers in this case though, as DHA is proven to be important for long-term cardiovascular health and eye and brain function.
Recommendation: Enough to supplement dietary intake, according to specific needs of your age and gender:
While it is true that the iron found in meat (heme iron) is better absorbed by the iron found in plants (non-heme iron), according to the article vegans do not have a higher rate of iron deficiency relative to omnivores. But this doesn’t mean it’s not a problem. A study of German vegans found up to 40% of young women suffering from iron deficiency anemia. 15 Worldwide, 80% of all people are estimated to be iron deficient, with anemia rates of up to 30%. 16 In China in 2002, 15.8% of men and 23.3% of females were anemic, with similar rates in urban and rural areas. 17 Rates of anemia for Chinese children living in rural areas is shockingly high, with one study showing an average of 34.5% in poor counties in Ningxia and Qinghai. 18
Iron deficiency is really not fun, trust me, I’ve been there. Fatigue, lack of energy, lowered immunity… the list of symptoms is long and unpleasant. Since women of childbearing age are especially at risk of iron deficiency, I take a 10 mg/d vegetarian iron supplement just to be on the safe side.
If you want to avoid taking yet another pill, vegan sources of iron are plentiful. Try also eat foods high in Vitamin C, which greatly improves the absorption of that non-heme plant iron.
Vegans tend to have lower zinc intake than omnivores, but don’t appear to suffer any particular health effects because of this. The phytates found in whole grains, seeds, and legumes bind to zinc and decrease its bioavailability, so vegans eating a lot of these foods may want to emphasize eating foods fortified or naturally rich in zinc.
Too many pills?
Yes, the list of supplements can sound overwhelming at first. However, with the exception of B12, these nutrients are generally important to consider for non-vegans as well. True, you can get all the nutrients you need from food, but I consider the recommended supplements here a “just in case” safety measure for your health.
Lest you be discouraged by the deficiencies common vegans mentioned above, let me list the overwhelming benefits of a vegan diet reported in the article (as compared to non-vegans)
- Higher intakes of the following nutrients: folic acid, fiber, vitamins C and E, potassium, magnesium, phytochemicals, iron
- Lower intake of saturated fat and overall calories
- Lower cholesterol levels (total + LDL)
- Lower blood pressure
To me the necessity of supplements is acceptable given the benefits of eating vegan. But if you really opposed to pills of any kind, you don’t need to go 100% vegan to improve your health. Most of the benefits of veganism are associated with increased fruit and vegetable, soy, legume, whole grain and nut intake. Increase these and cut out the processed foods and sugar, and you’re on your way to a better you.
- Craig WJ. Health effects of vegan diets. Am J Clin Nutr. 2009, 1627S-33S. ↩
- National Institute of Health and Dietary Supplement Fact Sheet: Vitamin B12. ↩
- Dietary Reference Intakes for Calcium and Vitamin D. Institute of Medicine, Nov 2010. ↩
- Lu L, et al. Plasma 25-Hydroxyvitamin D Concentration and Metabolic Syndrome Among Middle-AGed and Elderly Chinese Individuals. Diabetes Care. 32,7:1278-1283, 2009. ↩
- Dietary Reference Intakes for Calcium and Vitamin D. Institute of Medicine, Nov 2010. ↩
- Composition of Foods. USDA Nutrient Data Base for Standard Reference, Release 21. ↩
- Dietary Reference Intakes for Calcium and Vitamin D. Institute of Medicine, Nov 2010 ↩
- Dietary Supplement Fact Sheet: Calcium. Office of Dietary Supplements, National Instituted of Health. Updated 1/19/2011. ↩
- Bailey RL, Dodd KW, Goldman JA, Gahche JJ, Dwyer JT, Moshfegh AJ, Sempos CT, Picciano MF. Estimation of total usual calcium and vitamin D intakes in the United States. J Nutr. 2010 Apr;140-4:817-22. ↩
- He Y, Zhai F, Wang Z, Hu Y, et al. Status of dietary calcium intake of Chinese residents. National Institute of Nutrition and Food Safety, China CDC. Wei Sheng Yan Jiu 卫生研究. 2007 Sept; 36,5:600-2. ↩
- Kris-Etherton PM, Harris WS, Appel LJ. Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease. Circulation. 106:2747-2757, 2002. ↩
- Dietary Supplement Fact Sheet: Omega-3 Fatty Acids and Health. Office of Dietary Supplements, National Institutes of Health, Updated Oct 28, 2005. ↩
- Kris-Etherton PM. Harris WS, Appel LJ. Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease. Circulation. 106:2747-2757, 2002. ↩
- Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium and Zinc. Washington, DC: National Academy Press, 2001. ↩
- Waldmann A, Koschizke JW, Leitzmann C, Hahn A. “Dietary Iron Intake and Iron Status of German Female Vegans: Results of the German Vegan Study. Nutrition and Metabolism. 2004. 48,2:103-108. ↩
- Stoltzfus RJ. Defining iron-deficiency anemia in public health terms: reexamining the nature and magnitude of the public health problem. J Nutr 2001;131:565S-7S. ↩
- Piao J, Lai J, Xu S, et al. Study on the Anemia Status of Chinese Population. Institute of Nutrition and Food Safety, Chinese Center for Disease Control. Acta Nutrimental Sinica, 2005. ↩
- Luo R, Zhang L, Chengfang L, et al. Anemia in Rural China’s Elementary Schools: Prevalence and Correlates in Ningxia and Qinghai’s Poor Counties. Working Paper 215. Rural Education Action Project, Chinese Academy of Sciences. Feb 2010. ↩