Optimizing Your Vegan Diet

A well-planned vegan diet includes attention to certain key nutrients, in order to increase our chances for optimum health.

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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, the American Dietetic Association also asserts that poorly planned vegan diets may be low in vitamin B12, calcium, omega-3 fatty acids, vitamin D, iron, zinc, riboflavin (vitamin B2), and iodine.

The word is finally out and spreading rapidly, that a well-planned vegan diet, which consists of the avoidance of all animal products, is not only more ethical but also greatly lessens our susceptibility to many serious diseases, such as heart disease, cancer and diabetes.

Of course, following a vegan diet (even a well-planned one) is not enough to ensure that these diseases never occur. There are so many contributing factors to illness and health, including the air we breathe, the water we drink, the thoughts we think, the feelings we feel, the physical, emotional and spiritual environment in which we live, the genes we inherited from our parents and our parents’ parents, and likely a host of others that are, as yet, unknown.

And yet, there is little doubt that not only does what we choose not to eat have a profound effect on our health, but so does what we choose to eat instead. Thanks to the research of long-time vegan activist Butterflies Katz, we are now able to provide you with this lesser known information about certain nutrients that every human body needs and why, so we can ensure that our diet (which is one of the easiest factors for us to control) increases rather than decreases our chances for optimal health.

Vitamin K2

Vitamin K (found in dark leafy greens) is important for forming blood clots. However, new discoveries are showing that it also boosts bone density, reduces calcification of arteries and helps prevent certain cancers. Simply put, K2 directs calcium to bones rather than arteries, and has been shown to work well when combined with Vitamin D. Here’s the thing for vegans though: It is difficult to find in plant foods. 

So why don’t we hear about Vitamin K2 much in the vegan community? Because, like other nutrients, our bodies can convert Vitamin K1 to K2. However, some professionals are not convinced that we convert enough to cover our K2 requirements, and studies have shown 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 our bodies age, there is a reduction in vitamin K2 production, so it is recommended for vegans over 50 to take a supplement. Also, the use of antibiotics can deplete the Vitamin K2 in our body.

New recommendations for vegans are to consume the following fermented foods, which are the only known vegan food sources of K2:

  • sauerkraut (raw, homemade is best)
  • kefir in plant milk
  • unpasteurized kombucha
  • vegan kimchi
  • 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.) The recommended Vitamin K2 supplements are sourced from natto, not synthetic.

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.

For those who are concerned about their levels of Vitamin K, there are a number of vegan supplements available.

Vitamin D

Vitamin D is normally produced in the body from exposure to sunlight on the skin in animals’ bodies, including humans. If a vegan does not get regular sunshine exposure, they can get vitamin D by eating fortified vegan foods, or supplement.

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 and the season, as well as latitude. One study in Finland showed that the sunlight in winter was insufficient to maintain adequate Vitamin D levels in that region. In some locations and in winter, supplementation is an absolute must, either from fortified foods or a vegan supplement.

For optimal vitamin D production in winter, sun exposure should be at midday. The closer to solar noon, the more vitamin D is produced. The darker your skin, the more exposure to sunlight is required. Use of sunscreen diminishes Vitamin D3 production enormously or almost completely.

For vegans looking to supplement, there is information suggesting that D3 (usually animal sourced) is better, but there have been other studies disproving that theory. However, more and more vegan Vitamin D3 is being marketed in recent years.

Vitamin A

Ginny Messina, 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.”

However, to meet requirements, vegans need to consume plenty of carotenoids or beta-carotene rich foods such as:

  • carrot juice (an excellent source)
  • dark orange colored squashes or pumpkins
  • carrots
  • 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. A deficiency in Vitamin B12 can result in irreversible nerve deterioration and can even be fatal.

However, we only need minute amounts of B12, and it’s easy to obtain in a vegan way.

Rather than killing an animal to eat him/her for the B12 stored in their body, many vegans choose to take

  • a liquid B complex (with B12)
  • a liquid vegan sublingual B12 or a nugget or ‘dot’ (all proven effective)
  • B12 fortified nutritional (savory) yeast
  • fortified soy milks, etc.

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.

A vegan diet is considered to promote health and longevity and reduce the risk of cardiovascular diseases. But as explained by Virginia Messina, RD:

“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, a non-protein 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.” 


Contrary to popular belief, calcium isn’t too difficult to find in a vegan diet. However, since some studies have reported vegans falling short of recommended amounts of calcium, we do need to ensure we eat the foods that contain it! Some of these foods include:

  • kale, collard greens, bok choy, turnip and mustard greens, dandelion leaves
  • edamame, beans (especially navy beans) and tempeh
  • quinoa
  • almonds, hazelnuts and pistachio nuts
  • broccoli
  • dried figs
  • sesame seeds
  • blackstrap molasses
  • seaweeds such as kelp, wakame, and hijiki

Of course there are also plant milks and juices that are fortified with calcium. Calcium absorption from all of 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.


Iodine is an essential mineral that more than 30% of the worldwide population is not getting enough of. Scientific studies indicate that vegans might be falling short on iodine. Even a mild deficiency of this nutrient in children can have lifelong effects on IQ and learning ability.

The right amount of Iodine helps your thyroid function the way it should, and a deficiency can contribute to hair loss, among other problems. 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.

Other food sources are:

  • Cranberries
  • Sea vegetables such as kombu, arame, and hijiki
  • Himalayan salt or iodized salt
  • Navy beans and green (string) beans
  • Strawberries
  • Baked potato with the skins
  • Bananas

Sea vegetables are such a good source of iodine that it’s actually possible to exceed the safe levels of iodine by over consuming seaweeds. In addition, the amount of iodine in a serving of sea vegetables is not consistent. A serving of kombu, for instance, 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.

DHA/EPA (long chain fatty acids)

Once again, here is another example of how we make our own nutrients within our 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
  • organic canola oil.

Also, in lesser amounts, it is found in soybeans and some green vegetables such as Brussells sprouts, kale, butternut squash, spinach, etc. Walnuts have the most beneficial fatty acids in the nut kingdom, and studies have revealed they are just as effective as those sought in fish.

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 for older vegans and pregnant mothers. DHA supplements should be taken with caution, however, as they can raise total and LDL cholesterol.


Vegans are usually recommended to eat iron-rich foods 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 (also a 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.


Vegans have been shown through scientific research to have less taurine, a sulfur-containing molecule or an amino sulfonic acid 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, but scientists report that smaller amounts of taurine are also synthesized 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.

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 they are able to synthesize taurine from the 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, Brussels sprouts, oats, granola and wheat germs. B6 is 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 does advise 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. 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.

Some question whether ZINC and CHOLINE are nutrients that vegans should be concerned about. But after reading the studies, it doesn’t appear that vegans are falling short on them. This study, for instance, suggests that vegans may not have the same requirements for these nutrients 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.”



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© Gentle World 2023. Gentle World is a non-profit, 501(c)(3) educational organization, helping to build a more peaceful society by educating the public about the reasons for being vegan, the benefits of vegan living, and how to go about making the transition. EIN: 59-1999433