How to Avoid Nutrient Deficiencies on a Plant-Based Diet

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Vegetarian, vegan, and other plant-based diets can be incredibly healthy in many ways (even reversing heart disease in some cases), but certain important nutrients are decreased or even absent in these diets. Without careful consideration, deficiencies will develop, which can cause serious health problems.

I see this a lot in my acupuncture clinic, where my patients who are on a plant-based diet (especially veganism) commonly present with all of the signs and symptoms of (in Chinese Medicine terms) qi, blood, and yin deficiency. Insomnia, poor gut health and digestion, infertility, easily broken bones, and many other potential issues can develop from these particular deficiencies.

Here’s a simplified guide, based primarily on Western nutrition and dietetics, for clearly understanding how to get all the nutrients you need if you’re on a plant-based diet, so that it can be a really healthy choice. If you’re short on time, just check out the bolded words to see which nutrients are important to consider.

The #1 most important nutrient for vegetarians to have is Vitamin B12.

This is an essential vitamin which our bodies are unable to produce, and thus we require getting it from some outside source. It’s not possible to get B12 from any plant foods. Furthermore, “fermented foods (such as tempeh), nori, spirulina, chlorella algae, and unfortified nutritional yeast cannot be relied upon as adequate or practical sources of B-12.”

B12 fortified foods or supplements need to be consumed by vegetarians in order to not become deficient.

Vegetarians who don’t supplement with B12 might think and feel that they’re totally healthy, however, their unnoticed deficiency can later lead to “stroke, dementia, and poor bone health”, among other health problems. While having this deficiency, if they were tested, they would show as having elevated homocysteine levels despite feeling fairly normal. When the deficiency starts to become more severe, at the early stage there may be “unusual fatigue, tingling in the fingers or toes, poor cognition, poor digestion, and failure to thrive in small children” among other signs and symptoms. Worse problems can develop after that.

It’s important to eat B12 fortified foods or supplements twice per day, because B12 is only absorbed at half of the RDA (recommended daily allowance) at one time, and requires up to 6 hours before being able to absorb more. If just taking one B12 fortified food once per day, you’d only get half of what you needed for that day. Best to have it for breakfast and dinner in order to get the full amount.

For lacto-ovo vegetarians (those who include milk and eggs with a plant based diet), 1 cup of milk and 1 egg provides roughly 2/3rds of the RDA of Vitamin B12. For other types, such as vegans (those who are 100% plant based), they will need to find B12 fortified foods, or simply take a B12 supplement.

Here are some ideas of B12 fortified foods (make sure it says that it’s fortified on the package): soymilk, breakfast cereal, vegan meats, or Red Star vegetarian support nutritional yeast.

The second most important nutrient for vegetarians to consider is Vitamin D.

Especially in our area of West Michigan, we receive much less sunlight throughout the year, and as a result we tend to have more people with Vitamin D deficiency, especially during the winter and spring.

While it’s possible for our bodies to produce Vitamin D through exposure to the sun, that’s not a consistently reliable way to increase the nutrient for health. Supplementation, or eating fortified foods, is the best way to get enough Vitamin D.

Here are some examples of Vitamin D fortified foods (ensure that the package says it’s fortified): cow’s milk, some nondairy milks, some fruit juices, and some breakfast cereals. Eggs may provide some amount of Vitamin D. It’s also said that some mushrooms, when treated with UV light, can provide Vitamin D.

Vitamin D supplements are recommended for those who can’t receive enough via sunlight and the diet, especially for older adults (who become less able to synthesize B12 from the sun) and especially during winter and spring months. Some experts recommend daily intakes of 1000-2000 IU or even more.

I personally recommend taking supplements all year round for my patients, rather than trying to get it from fortified foods, given that we live in an area of the country that receives quite a bit less sunlight compared to other areas throughout the year.

Low intake of Vitamin D (as well as Vitamin B12) has been linked to “low bone mineral density, increased fracture risk, and osteoporosis”, and vegans have been shown to have the lowest bone mineral density in comparison to other types of vegetarians, who may be slightly reduced compared to omnivores. For bone health, it’s important to get not just vitamins D and B12, but also adequate calcium and protein.

Aside from keeping bones healthy, Vitamin D also influences a large number of metabolic pathways. So, it’s very important to ensure that you’re getting enough of it for good health. Again, I recommend taking a Vitamin D supplement.

Omega 3 essential fatty acids (EPA and DHA) are the third most important consideration for vegetarians.

EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), also known as “omega 3 fatty acids”, can be significantly lower in vegetarians compared to omnivores. For vegans, they may end up having no dietary intake of these essential nutrients.

These fatty acids are important for “the development and maintenance of the brain, retina, and cell membranes”, and they can “favorably impact pregnancy outcomes”, the “risk for cardiovascular disease”, among other issues.

For healthy people, EPA and DHA can be produced sufficiently in the body by ingesting ALA (alpha-linolenic acid), although that process can be affected by differences in sex, dietary composition, health status (hypertension and diabetes are some examples of decreased health status, which may interfere), and increased age.

Also, higher intakes of LA (linoleic acid, the most predominant omega 6 fatty acid), which is present in various foods, might interfere with ALA’s production of EPA and DHA. It’s thought to be best to make sure that LA doesn’t exceed 4 times the amount of ALA (4:1 ratio of LA to ALA), to ensure that ALA can convert to EPA and DHA.

Vegetarians and vegans might consume roughly the same amount of ALA as omnivores (despite consuming less EPA and DHA directly), but they may end up producing less EPA and DHA from the ALA, resulting in deficiencies.

Plant sources of ALA are: seeds (flax, chia, camelina, canola, and hemp), walnuts, and their oils. The dietary reference intake for ALA is 1.6g/day for men, and 1.1g/day for women, although those on plant-based diets may need to ensure somewhat higher intakes of ALA, and be careful to reduce (but not eliminate) their amount of foods with LA.

While omnivores can eat fish and take fish oil for ingesting DHA and EPA directly, for vegetarians there are low-dose microalgae based supplements for DHA and EPA. I recommend taking a supplement to ensure that your omega 3 needs are met.

The breastmilk of vegetarian mothers has been shown to be low in DHA, and also, infants of vegetarian mothers have been shown to have low plasma DHA. This is potentially not good for the baby’s health, as it has to do with its brain development and the proper functioning of its cell membranes. Pregnant and lactating vegetarians should especially supplement with microalgae DHA and EPA, rather than trying to rely on dietary sources of ALA alone.

The fourth most important nutrient to pay attention to is iodine.

Those on plant-based diets are at risk of deficiency of this important nutrient.

Sea vegetables and dairy can contain iodine, but the amounts vary, and aren’t reliable.

Iodized salt is a great and easy source for getting iodine, and it’s vegan. Normal sea salt, kosher salt, and other types of seasonings such as tamari typically don’t contain iodine. There are some brands which are iodized; for instance, I have an iodized sea salt. Make sure the label says it.

Adults shouldn’t get close to exceeding 1100 micrograms per day of iodine, which is the tolerable upper intake level. Vegan women of childbearing age should take 150 micrograms per day, either of an iodine supplement, or about 3/8ths of a teaspoon of iodized salt.

Next on the list, and of great importance, is lysine.

A complete protein is made up of various amino acids, and for the plant-based diet, the amino acid lysine tends to be the one that comes up short. While the body produces some amino acids, it unfortunately doesn’t produce this particular one, and we therefore need to take it in from outside sources in order to have a complete protein. While vegetarians might be getting enough (incomplete) protein in their diets, enough to maintain muscle mass at least, it may not be a truly complete protein; this can cause some health problems if there is a deficiency in this amino acid, because protein and the amino acids do way more than simply build and maintain muscle. Lysine is essential for the proper healthy functioning of the body (for instance, calcium absorption, preventing anemia, fatty acid metabolism, etc). Without it, we start to malfunction in many ways.

There are many plant foods that contain lysine to some degree, but in comparison to an omnivorous diet, it’s in much smaller amounts. The vegan has to be especially careful to ensure they’re getting enough lysine in their diet.

Here are some common plant-based sources of proteins that have more of the amino acid lysine: quinoa, lentils, beans (navy, kidney, black, etc), tempeh, soy milk, pistachios, and pumpkin seeds. Still, compared to meat in the omnivorous diet, these sources contain much less lysine.

For vegan protein powders, pea protein contains more lysine than any other types. I recommend supplementing the plant-based diet with this type of protein powder, since in my opinion it’s hard to get a good amount of lysine by solely using the dietary sources; trying to do it by food only would require eating those things (like lentils and beans) more often than would be enjoyable. Instead, take pea protein powder in addition to using these food sources more often.

Finally, three more nutrients that vegetarians need to be careful about getting are: iron, calcium, and zinc.

Iron levels tend to be lower in those on a plant-based diet. Meat contains heme iron, which has a tendency to be more readily absorbed, whereas plant foods contain nonheme iron. A vegetarian might technically eat the same amount of iron as an omnivore, in nonheme form, but due to the possibility of decreased bioavailability, they may be absorbing less of it into their system, in some cases leading to iron deficiency. It’s not always true that nonheme is less bioavailable than heme iron, but it can vary greatly depending on serum ferritin levels and dietary modifiers.

Phytates, polyphenolics, and enhancers such as Vitamin C (all of which are dietary modifiers) can impact absorption of iron for better or worse. For vegetarians, taking special care to increase iron and make it more bioavailable in their diet can play a big role in their ability to absorb it from nonheme sources, although the effectiveness of dietary enhancers can decrease over time, leading to possibly needing to supplement the iron at some point.

Calcium intake is normal for lacto ovo vegetarians, but for vegans it can fall below the recommended amount and lead to deficiencies. The bioavailability of calcium in plant foods depends on oxalates, phytates, and fiber. High oxalate foods can lead to poor absorption of calcium (such as spinach, beet greens, and swiss chard)…despite their high calcium content, they are not good sources of dietary calcium due to the oxalates.

Low oxalate vegetables (such as kale, turnip greens, Chinese cabbage, and bok choy) are much better sources of calcium, and have a fractional absorption of 50%. “Absorption from calcium-set tofu (made with a calcium salt) and from most fortified plant milks is similar to that of cow’s milk, at approximately 30%.” Decent foods, at about 20% absorption, are: white beans, almonds, tahini, figs, and oranges. Registered Dieticians can help with recommendations of good food sources of calcium, as well as recommend low dose calcium supplements.

Finally, zinc levels are often slightly lower in vegetarians, while still remaining in the “normal” range. While the levels typically aren’t deficient for those on the plant based diet, for optimum health, one may want to pay attention to increasing the food supply of this nutrient. Dietary sources are: soy products, legumes, grains, cheese, seeds, and nuts. Soaking and sprouting some of these things (like beans and grains) may help increase the absorption of zinc, due to reducing the binding of zinc by phytic acid. Citric acids can also help with zinc absorption to some extent.

So to reiterate, these are all of the nutrients that those on a plant-based diet should consider carefully (in order of importance):

  • Vitamin B12
  • Vitamin D
  • Omega 3s (EPA and DHA)
  • Iodine
  • Lysine
  • Iron
  • Calcium
  • and Zinc

I’d be interested to see if Chinese Medicine diagnosis (such as pulse and tongue diagnosis) would still point toward signs of qi, blood, and yin deficiency if those on a plant-based diet optimally incorporated all of these nutrients listed above. I suspect they might no longer be deficient. If there were still signs of deficiency, there are Chinese herbal medicine formulas that would easily nourish these substances back to normal levels.

Taking Chinese medicinal herbs, in addition to ensuring that your foods and supplements supply all of these important nutrients, is the approach that I recommend for those who are on a plant-based diet.

Sources (this wasn’t an academic blog post, but was more for the purpose of helping my patients easily see which nutrients to think about):

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