The American Dietetic Association and Dietitians of Canada state that ‘properly planned vegan diets are nutritionally adequate for all stages of life, including pregnancy and lactation, and provide health benefits in the treatment and prevention of certain diseases.’ However, poorly planned vegan diets may be low in vitamin B12, calcium, omega-3 fatty acids, vitamin D, iron, zinc, riboflavin (vitamin B2), and iodine, according to the American Dietetic Association. It’s important to note that the non-vegan diet of the average American is deficient in calcium, iodine, Vitamin C, Vitamin E, fiber, folate, and magnesium, according to USDA Food and Nutrient Intakes by Individuals in the United States. Recent studies claim that many people; both vegan and non-vegan, are Vitamin D deficient. Source
I know vegans who say 'just eat all the colors and don't worry about it; a plant-powered diet is our natural diet.' While others prefer scientific data. I am on both sides. I became vegan before personal health benefits were discovered. However, I also want to heed this scientific research and help keep the vegan community informed of possible and preventable pitfalls. Because I so want vegans to live long-term, optimally healthy lives, I've extensively researched and have put together this checklist of potential nutrient deficiencies in vegans or those who eat 100% plant-based - and the best way to overcome them. From reading scientific studies comparing vegans and nonvegans, we can gain insight and take precautions based on these findings, however we don't really know. For example, I read a study that allowed for the participants to eat animal "foods" one day a week and still be called 'vegan' for that study. Some studies combine vegetarians and vegans in one grouping. They may not be totally accurate. This post is not meant to scare anyone from vegan eating, I implore anyone to eat and live vegan. I am living proof we humans can live healthy vegan lives, long-term; and that speaks louder than anything I might read online. And I (erroneously) never took B12 or any supplement for the first 25 years (and I was vegetarian 10 years prior to becoming vegan). Nor did I eat flax or hemp seeds, or walnuts; foods that are particularly important for vegans to consume in a well-planned vegan diet. So obviously vegans thrive.
Studies have shown vegans to have a lower incidence of stroke, and a lower risk of mortality from stroke and ischemic heart disease. To learn more about the protective advantages of vegan diets, go here ~ Sadly, in real life though, I have personally known vegans to die from cardiovascular disease at too young of age, and stroke, and cancer. Vegan diets also have some nutrient disadvantages. While it is true that it might be "easier" getting some nutrients from eating other animals who made those nutrients in their bodies, vegans don't think it's reasonable to exploit, objectify, steal from, or be violent to animals, and therefore have figured out how to get our required nutrients without animal abuse.
There are world record-breaking and champion vegan athletes. There are vegans who have dreaded diseases. They are all vegans, because veganism is about respecting animals and not participating in their exploitation for food, clothing, products and practices. It stands to reason that if you stop consuming corpses and milk meant by nature for newborn calves, not humans - you are going to feel better. The majority of vegans do feel healthier once eliminating animal's milk, eggs, and flesh. Because of that, I used to believe it was a mighty cure-all until I began witnessing vegan friends and fellow advocates getting cancer, or heart failure at age 66. "Shit Happens" - to vegans and non-vegans. Not all illnesses are diet-related. Not all vegans eat an optimal or well planned diet. Some could have conditions that stemmed from their non-vegan years. Genetics could be the reason why some vegans have particular issues, and they may have been propelled longer than expected because of their vegan diet, in some cases.
I would never suggest to anyone for any reason to be nonvegan. Be vegan and be informed about vegan nutrition. Some of the following nutrients may be lacking more in a vegan's diet, while some are problematic for the general population. What scientists won't say and can't say because they don't know themselves, is that perhaps a vegan's body has different needs or requirements to that of animal eaters; who we are being compared to in blood and other tests. One study I read verified that theory. Or perhaps nutrients are being utilized by the vegan's body and therefore there is not so much in the bloodstream, but we are being compared by blood tests.
VITAMIN K2 - Vitamin K (found in dark leafy greens) is important for forming blood clots, however new discoveries of Vitamin K2 are showing that it boosts bone density, reduces calcification of arteries and helps prevent certain cancers. K2 directs calcium to bones and not arteries, and has been shown to work well with Vitamin D. It is difficult to find in plant foods. "Woefully unknown to the public and mainstream health experts alike, vitamin K2 is critical for a healthy heart and skeletal system. Among other things, it helps shuttle calcium out of your arteries (where it contributes to plaque formation) and into your bones and teeth, where it rightfully belongs." source ~ So why don't we hear about Vitamin K2 much in the vegan community? Because, like other nutrients, we convert Vitamin K1 to K2. One study concluded: "This study provided direct evidence for the absorption of vitamin K2 from the distal small bowel, supporting a definite role for bacterially synthesized vitamin K2 in contributing to the human nutritional requirements of this vitamin." In other words - we make our own K2 in our own bodies. Some are not convinced that we convert enough to cover our K2 requirements, and studies show that for bone density and cardiovascular benefits, the K2 should come directly as K2 from a food or supplement source, rather than being converted from Vitamin K1. As we age there is a reduction in vitamin K2 production, therefore it is recommended for vegans over 50 to supplement. New recommendations for vegans are to consume the following fermented foods; the only vegan food sources of K2: sauerkraut (raw, homemade is best), kefir in plant milk, unpasteurized kombucha, vegan kimchi, and natto (the best food source, if vegans could find it and learn to like it. In Japan where it is commonly eaten, studies have proven substantial benefits from consuming it.) These fermented foods (not tempeh or miso, though) are also possible sources of real Vitamin B12 and are definitely sources of beneficial bacteria or probiotics. Also, use of antibiotics can deplete the Vitamin K2 in our body. ~ If you eat a raw food vegan diet or are pregnant or raising young children, see here: this post. Vegan K2 supplement - Vegan K2 Supplement - Doctor's Best Vitamin K2 MenaQ7 food sourced from Natto - Vegan algae-derived calcium and K2 for bone health - New Research on Vitamin K2 - Country Life Strawberry flavored vegan K2
VITAMIN D – is normally produced in the body from exposure to sunlight on the skin in animal's bodies, including humans. If a vegan does not get regular sunshine exposure, they should eat fortified vegan foods, or supplement Vitamin D2 (the widely available vegan version of D). There is information stating that (usually animal sourced) D3 is better (link), but here is a medical study disproving that theory. Of recent years, more and more NEW Vegan Vitamin D3 is being marketed. This is to supply a demand for vegans who want D3, but not from an animal - and don't get enough sunshine. Here are some links of Vegan Vitamin D3: Link Link Link Link Link Link ~~ The production of Vitamin D3 out of sunlight on our skin is influenced by a number of factors, such as the angle of the sun's light, the time of day, the season, as well as latitude. For example, one study in Finland showed that the sunlight in winter was insufficient to maintain adequate Vitamin D levels in vegans of that region. In some locations and in winter, supplementation is an absolute must for vegans, either from fortified foods or a vegan supplement. For optimal vitamin D production in winter, sun exposure should be midday. The closer to solar noon, the more vitamin D produced. The darker your skin the more exposure to sunlight is required. People with white skin, will need around 15 minutes of sun exposure a day whereas those with dark skin will need longer - perhaps up to 1.5 hours. At least 40% of the entire skin surface should be exposed for optimal vitamin D production, the torso being the most productive. Use of sunscreen diminishes Vitamin D3 production enormously or almost completely. ~ Also, some brands such as Monterey Mushrooms are the only plant-based foods that contain natural Vitamin D as they are exposed to ultraviolet rays.
VITAMIN A - The Vegan R.D. (registered dietitian) informs us: "It’s true that the preformed active type of this vitamin is found only in animal foods. But plants are abundant in vitamin A precursors such as beta-carotene. In fact, these provitamin A compounds are important enough that the USDA measures vitamin A content of foods as “retinol activity equivalents (RAE),” which includes both preformed vitamin A and the compounds that the body turns into vitamin A. There is no separate RDA or recommendation for animal-derived pre-formed vitamin A." Source link - However, to meet requirements, vegans need to consume plenty of carotenoids or beta-carotene rich foods such as carrot juice (excellent source), dark orange colored squashes and pumpkins, carrots, and sweet potatoes. These precursors to Vitamin A are also found in lesser amounts in spinach, cantaloupe, kale, broccoli, mango, and apricots.
VITAMIN B12 – no matter where it is sourced from, Vitamin B12 is produced by microorganisms; either in the small intestines of humans or other animals - or in laboratories. Rather than killing a cow or a pig to eat him/her for the B12 stored in their gut, vegans choose to take a liquid B complex (with B12) or a liquid vegan sublingual B12 or a nugget or 'dot' (all proven effective), and sprinkle B12 fortified good tasting nutritional (savoury) yeast on their meals, drink fortified soy milks, etc. A deficiency in Vitamin B12 can result in irreversible nerve deterioration and even be fatal, however we only need minute amounts of B12. Deficiency of B12 is not just a vegan issue. "If you are over age 50, the Institute of Medicine advises that you get extra B12 from a supplement. Up to 30 percent of adults aged 50 years and older may be unable to normally absorb Vitamin B12 in food. However, they are able to absorb the vitamin B-12 added to fortified foods and supplements. Supplements and fortified foods may be the best sources of vitamin B-12 for adults older than age 50 years. ~~ A vegan diet is considered to promote health and longevity and reduce the risk of cardiovascular diseases. One study reveals that a plant-based diet may cause the rise of plasma homocysteine concentration if B vitamins are deficient. Raised homocysteine levels are linked with heart disease. Elevated homocysteine concentration in plasma was observed in 66% of the vegans and 45-50% of the omnivores or vegetarians. The vegan subjects had significantly higher mean plasma homocysteine levels than omnivores, who also had elevated levels. Conclusion: "Thiamin and folate need not be a problem in a well-planned vegan diet. Vitamins B(12) and B(2) may need attention in the strict vegan diet, especially regarding elevated homocysteine levels in plasma." Here's a second source reporting: “But there is room for improvement in any diet, and the analysis, published in the Journal of Agricultural and Food Chemistry, suggested that vegans who have low intakes of vitamin B12 and possibly omega-3 fats could lose out on the benefits of healthful plant-based eating. Inadequate B12 is associated with elevated levels of homocysteine, an amino acid that is linked to increased heart disease. But that's an issue only for vegans who fail to supplement with vitamin B12. Those who consume recommended amounts of B12 have healthy levels of homocysteine.” Further Reading on Vegans and Vitmain B12
CALCIUM - should not be too difficult to find in a vegan diet, but you need to ensure you consume collard greens, dried figs, tempeh, kale, dandelion leaves, turnip and mustard greens, sesame seeds, quinoa, tempeh, green soy beans cooked, blackstrap molasses, almonds, broccoli, bok choy, Navy and other beans, seaweeds such as kelp, wakame, and hijiki, hazelnuts and pistachio nuts, fortified plant milks and juices. Calcium absorption from these foods is excellent. It is interesting to note that cows obtain all the calcium they require for their large bodies and to feed their offspring - from a very limited plant diet. Some studies have reported vegans falling short of recommended amounts of calcium. Link
IODINE is an essential mineral that more than 30% of the worldwide population is not getting enough and vegans might be at higher risk. Scientific studies indicate vegans are falling short on iodine. Even a mild deficiency of this nutrient in children can have lifelong effects on IQ and learning ability. (source) The right amount of Iodine helps your thyroid function the way it should. Obviously iodine is missing in soils or they would not add iodine to some table salt for the general public. However many vegans don't consume iodized salt. Sea vegetables are a good source of iodine and you can even overconsume and exceed the safe levels of iodine consumption. I am a long term vegan and I never consume seaweed or iodized salt. When I took a urine test to check for iodine, I did fall slightly short of the normal. I briefly supplemented; then researched foods with iodine and include them in my diet now. Some seaweeds and cranberries are very high in iodine. Other food sources are Himalayan salt, iodized salt, Navy beans, baked potato with the skins, green (string) beans, and bananas. Iodine is essential for the thyroid gland to work properly, and I have heard of vegans with thyroid issues over the years. A deficiency can contribute to hair loss, among other problems. Sea vegetables such as kombu, arame, and hijiki are rich sources of iodine although the amount of iodine in a serving of sea vegetables is not consistent. A serving of kombu, may contain more than is considered safe for daily use. Long-term excessive iodine intake can be just as harmful as insufficient iodine. Don't overdo sea vegetables, especially if you are pregnant or breastfeeding. More on Vegans and Iodine
DHA/EPA - Plasma concentrations of DHA/EPA (long chain fatty acids) have been shown to be lower in vegans. It did not matter the duration of adherence to a vegan diet. Once again, here is another example of making our own nutrients within our own bodies. We can convert short chain fatty acid ALA (alpha-linoleic acid) into long chain fatty acids. The conclusion from this study suggests that when animal "foods" are wholly excluded from the diet, the endogenous production of EPA and DHA results in low but stable plasma concentrations of these fatty acids. ~~ In order for vegans to reach the omega 3 fatty acid requirements, it is recommended by some researchers to include foods rich in ALA (alpha-linoleic acid) such as, in order from containing the most to the least: chia seeds, kiwi fruit seeds, Perilla, Flax seeds, Purslane, hemp seeds and oil, and organic canola oil. Also in lesser amounts, it is found in soybeans and some green vegetables such as brussel sprouts, kale, butternut squash, spinach, etc. Walnuts have the most beneficial fatty acids in the nut kingdom. Studies reveal they are just as effective as fish. See here. Humans can directly consume the algae that the fish have consumed that made them "good sources of omega 3 fats". Many vegans are now supplementing with, non-synthetic, but algae-derived DHA / EPA, as is recommended; especially older vegans and pregnant mothers. DHA supplements should be taken with caution, as they can raise total and LDL cholesterol. For a detailed post on vegans and DHA/EPA omega 3 fats, link
IRON - Vegans are recommended to eat iron-rich foods and vitamin C daily. However in several studies, vegans were not found to suffer from iron-deficiency any more than non-vegans. "Dried beans and dark green leafy vegetables are especially good sources of iron, even better on a per calorie basis than meat. Iron absorption is increased markedly by eating foods containing vitamin C along with foods containing iron. Vegetarians do not have a higher incidence of iron deficiency than do meat eaters" says Reed Mangels, PhD and registered dietician. Many vegetables, such as broccoli, spinach and bok choy, which are high in iron, are also high in vitamin C which aids iron absorption.
TAURINE - Vegans have been shown through scientific research to have less taurine; generally found in animal tissue. Taurine is essential for cardiovascular function, and development and function of skeletal muscle, the retina, and the central nervous system. With nonvegans, diet is the main source of taurine, a sulfur-containing molecule or an amino sulfonic acid. Scientists report that smaller amounts of taurine are also synthesized endogenously in the liver from methionine and cysteine; both found in soy. We vegans seem to make our own compounds, vitamins, long-chain fatty acids and other nutrients similar to herbivorous animals. Omnivores are literally stealing the lives of other beings so they can eat the taurine and other nutrients that these animals made in their own bodies. Vegans would not be getting much if any from food, so would be relying on what they make in their own body or synthetic supplementation. Vegans don't generally supplement taurine, but they do supplement it in the diet of dogs/cats fed vegan. Vegans should eat complete protein foods such as soy, hemp seed, quinoa, buckwheat, amaranth regularly to ensure you are able to synthesize taurine from amino acids found in these foods. Adults can produce taurine by a combination of cysteine with the help of pyridoxine-Vitamin B6, methionine and vitamin C. Cysteine is found in red peppers, garlic, onions, broccoli, Brussel sprouts, oats, granola and wheat germs. B6 in whole grain products, vegetables, and nuts. High levels of methionine can be found in Brazil nuts, sunflower seeds and butter, sesame seeds, oats and a huge long list of vegan foods. However, some scientific research advises vegans to supplement taurine.
CARNITINE is a non-essential amino acid because it is synthesized in our body from other nutrients. The highest food sources are animal tissue, but the best vegan food source is tempeh, which is quite high in carnitine. Other vegan foods that have much smaller amounts, but still provide carnitine are avocado, whole wheat bread, asparagus, macaroni, rice, and peanut butter. Vegans don't generally supplement carnitine, but some do and it is supplemented in the diet of dogs fed vegan. Link
Some have mentioned ZINC and CHOLINE - but after reading the studies, it does not appear that vegans are falling short on them. This study proved my theory that vegans have different bodily processes, and may not have the same requirements as animal eaters. "Despite the apparent lower bioavailability of zinc, copper, manganese, and selenium in vegetarian diets because of the high contents of phytic acid and/or dietary fiber and the low content of flesh foods in the diet, the trace element status of most adult vegetarians appears to be adequate."