According to a nationwide poll conducted in 2006 by Harris Interactive, 1.4 percent of Americans are vegan. Vegans avoid all types of meat, fish, and animal-derived products such as eggs and dairy. For comparison, 3.2 percent of Americans, or a little over double the number of vegans, follow a vegetarian-based diet, according to a 2008 Vegetarian Times study. Vegetarians eat plant-based foods, but also include dairy and/or eggs in their diet. Reasons for following a vegan diet include ethical such as animal welfare or environmental concerns, health reasons, or because of religious or cultural beliefs. As a dietitian, I believe every adult has the right to choose how she or he wishes to eat. My job is to help clients be the healthiest they can be with whichever way of eating they have chosen, be it vegan, paleo, omnivore, and everything in between. With that in mind, I would like to emphasize three nutrients that may be low or missing in a vegan diet. *
This is probably the number one key nutrient we think of when it comes to deficiencies. The prevalence of B12 deficiency is much higher in vegans than in vegetarians or omnivores. That is because natural B12 is only found in animals and animal products. There is a common misconception that B12 can be found in foods such as spirulina, nutritional yeast, seaweed, and fermented soy products. These foods contain B12 analogs, which mimic real B12 and actually increase the need for B12 in the body. B12 is needed for red blood cell production, the myelin sheath, and DNA synthesis. Deficiency therefore can lead to anemia, fatigue, mood disturbances including depression, muscle weakness and tingling in hands and feet, among many other symptoms. Vegan-friendly food sources are limited to fortified foods such as some cereals dairy-free milks. Supplementation is therefore very important for this essential nutrient.
EPA and DHA are essential (the body cannot make them) omega-3 fats that have become buzzwords in the last few years. Vegans have lower levels of EPA and DHA compared to omnivores. Adults who consume more DHA have a decreased risk of many diseases, especially neurodegenerative ones like Alzheimer’s and psychological disorders like depression, psychosis, schizophrenia, as well as cancers, asthma, autoimmune diseases, ADHD, among others. In addition, DHA is crucial for fetal and childhood brain development and is a strong predictor of intelligence and problem solving skills. That is why vegan diets during pregnancy, infancy, and childhood can be cause for concern. EPA and DHA are only found in fatty fish (and fish oil) such as salmon, mackerel, sardines, trout, herring, tuna, as well as some other seafood.
A precursor to EPA and DHA, ALA, is found in plant oils such as from flax seeds, hemp seeds, pumpkin seeds, and walnuts, and some in soybean and canola oils. The conversion of ALA into EPA/DHA is not an efficient process: less than 5 to 10 percent for EPA and 2 to 5 percent for DHA. This is by some estimates the absolute best-case scenario. The unfortunate conclusion is that the plant form of omega-3s are usually not sufficient in commonly consumed quantities to provide our bodies with the crucial EPA and DHA needed for optimal health. DHA supplements are therefore important and are available in a vegan-friendly option made from microalgae.
A, D, K2
The fat-soluble vitamins A, D, and K2 are less readily available on a vegan diet since they are mostly found in animal products. Vitamin A is needed for healthy skin, fertility, immunity, and eye health. Good sources include animal products like meat, dairy, and eggs, but is especially high in organ meats like liver and liver oil. While vegan diets are usually (hopefully) plentiful in carotenoids like beta-carotene from orange fruits and leafy green vegetables, the conversion into the active Vitamin A form is much less efficient than once thought. To maximize conversion, make sure to eat some fat with your vegetables, and have some of them cooked. Or, make sure to consume fortified foods or supplements.
Many of us by now have heard of the importance of Vitamin D and how deficiencies are all too common. Vitamin D is important for calcium absorption, bone health, neuromuscular function, immune health, reduction of inflammation, and modulation of cell growth and differentiation. Vitamin D can be obtained from spending time in sunlight, but this can be difficult in more northern latitude countries. It is found naturally in few foods - mostly fatty fish and fish oil. There are certain mushrooms placed under ultraviolet light that produce Vitamin D as well, however, they may be difficult to source, and contain a form of Vitamin D that is less well absorbed. Again, supplementation or eating fortified foods are the best options for vegans.
Vitamin K2 is a newly recognized vitamin (not to be confused with K1, which is found in leafy greens) that is important for heart and bone health. One good vegan source is natto, a fermented soybean product commonly found in Japan. However, the intense flavor and odor can be off putting to some, and it is not readily available in stores. Other rich sources include organ meat, such as liver, certain meats such as goose meat, egg yolks, and whole-milk dairy from pasture-raised animals, especially hard cheeses. Supplementation is a good choice if natto is not regularly consumed.
While a complete list is beyond the scope of this article, B12, omega-3s, and fat-soluble vitamins are commonly low in vegan diets. The good news is that supplements do exist for the nutrients vegans cannot get from food. In addition, many vegan-friendly foods are supplemented with at least some of the above nutrients, including breakfast cereals, juices, non-dairy milks, and snack bars. However, it is best to not rely on these foods – they often contain cheaper, less well-absorbed forms of the nutrients and omega-3 fats in particular may be damaged during processing. While they may not be able to get them all from whole foods, with forethought and careful planning, vegan adults can still get these nutrients from supplementation.
*Please note – this is not a complete list and the recommendations within this article do not pertain to infants or children.
The information provided in this article is intended for general use only and is not to be used in place of medical advice from a licensed health professional.