If you are thinking about adopting a plant-based lifestyle you may be wondering if you will need to take any supplements, since you will be cutting out meat and dairy from your diet. 

Most people are very concerned about protein. Rest assured, you can get all your protein from plants! If you haven’t read my blog post about protein, make sure you read that now.

Vitamin B12

The most important supplement that all vegans and vegetarians should take is B12. Vitamin B12 is needed for red blood cell formation and to help with the function of the central nervous system (Craig et. al. 2021).

Eating a plant-based diet has the benefit of consuming many nutrients and minerals. However, the one vitamin that you can’t get from plants is B12. Compared to omnivores, vegans are often vitamin B12 deficient.

Vitamin B12 is naturally found in animal foods and bacteria. Animals get the vitamin from eating foods that have bacteria on them. In our modern day society we wash and clean and then cook our food so we reduce or eliminate the vitamin B12 content. So if you aren’t eating any animals, you are at risk of developing a vitamin B12 deficiency. Older adults are also at risk of deficiency because absorption often decreases with age (Smolin et al., 2020).

B12 deficiency is serious. It can cause anemia and nerve damage, as well as mood disorders and difficulty with concentration (Craig, 2009). Luckily, this can be prevented by eating fortified foods, nutritional yeast or the easiest way is by taking a B12 supplement. My own family takes a daily supplement. I would also recommend regular bloodwork to check your B12 levels.

Vitamin D

You may also want to supplement with a daily dose of vitamin D. Many people, including omnivores, are deficient in vitamin D. If you live in the Northern Hemisphere or spend a lot of time indoors, you should definitely consider a supplement. Your doctor can test your blood levels if you are wondering if you get enough.

Vitamin D is important for your immunity, reduces inflammation, and helps your mood and memory. Vitamin D also increases calcium absorption and regulates bone mineralization so it’s important for bone health. You can read more about Vitamin D and bone health here.

Unfortunately, very few foods contain vitamin D, unless they are fortified. Some foods to look out for: fortified plant-based milks, mushrooms, fortified cereals and oatmeal, and fortified orange juice.

In addition to fortified foods and supplements, you can get vitamin D from exposing your skin (no sunscreen) to the sun for about 15 minutes a day.

Iron

Iron is important for immune function and thyroid health. Menstruating adolescents who eat low-energy diets, vegetarians, and vegans are all at risk of iron deficiency (Hercberg, et al., 2001).

It is a common misconception that iron is only abundant in animal-based foods. Plant-based sources of iron can be just as effective in meeting your nutritional needs.

Plant-based iron sources like lentils, tofu, beans, spinach, and fortified cereals can provide the iron your body requires. However, it's vital to pair these foods with vitamin C-rich options, such as citrus fruits or bell peppers, to enhance iron absorption.

Iodine

Iodine is important for regulating the thyroid. Some studies have shown that vegan diets are low in iodine (Menal-Puey, 2018). If you don’t need to carefully watch your sodium intake, you could use some iodized salt when cooking. In addition, seaweed, some grain products and some fruits and vegetables also have iodine.

Bottom Line

It is a good idea for vegans (and omnivores) to get regular bloodwork to check for deficiencies. If deficiencies are found then work can be done to add supplements and modify the diet. Everyone who eats a plant-based diet needs to take a B12 supplement and anyone who lives in the Northern Hemisphere or spends a lot of time indoors should take vitamin D.

References:

Craig W. J. (2009). Health effects of vegan diets. The American journal of clinical nutrition, 89(5), 1627S–1633S. https://doi.org/10.3945/ajcn.2009.26736N

Craig, W. J., Mangels, A. R., Fresán, U., Marsh, K., Miles, F. L., Saunders, A. V., Haddad, E. H., Heskey, C. E., Johnston, P., Larson-Meyer, E., & Orlich, M. (2021). The Safe and Effective Use of Plant-Based Diets with Guidelines for Health Professionals. Nutrients, 13(11), 4144. https://doi.org/10.3390/nu13114144

Hercberg, S., Preziosi, P., & Galan, P. (2001). Iron deficiency in Europe. Public health nutrition, 4(2B), 537–545. https://doi.org/10.1079/phn2001139

Menal-Puey, S., Martínez-Biarge, M., & Marques-Lopes, I. (2018). Developing a Food Exchange System for Meal Planning in Vegan Children and Adolescents. Nutrients, 11(1), 43. https://doi.org/10.3390/nu11010043

Smolin, L. A., Grosvenor, M. B., & Gurfinkel, D. (2020). Nutrition: Science and Applications. John Wiley & Sons.