MEETING NUTRITION NEEDS ON A VEGETARIAN OR VEGAN DIET

Many people are embracing the consumption of plant-based foods,¹ chiefly plant protein alternatives, and approximately 3% of Americans are vegetarian or vegan.² While it is possible to attain all essential nutrients on a vegetarian or vegan diet, some planning and supplementation are likely required.

Most vegetarians and vegans have no trouble meeting macronutrient needs. Many plant foods, such as grains, potatoes, and fruit, are rich in carbohydrates. Protein is plentiful in legumes including soy, peanuts, lentils, and beans, and fat can be found in avocados, olives, nuts, and seeds.

While many micronutrients are abundant in plant foods, there are a handful that vegetarians and vegans need to be extra diligent about consuming. Nevertheless, vegetarians and vegans can meet all nutrient intake recommendations through a balanced eating pattern that includes fortified foods and dietary supplements.

The Plate Method

The United States Department of Agriculture’s MyPlate can be adapted to fit a vegetarian or vegan diet. MyPlate outlines a balanced meal and depicts a plate consisting of approximately ½ fruits and vegetables, ¼ grains, and ¼ protein foods, as well as 1 serving of dairy.³ Vegetarians and vegans can select plant-based options for protein foods and vegans may choose calcium fortified soymilk in place of dairy.

There are a few iterations of vegetarian or vegan versions of MyPlate, including The Plant Plate by Virginia Messina, MPH, RD, and The Vegan Plate by Brenda Davis, RD, and Vesanto Melina, MS, RD.^4,5

Protein and Amino Acids

While all plant foods contain some amount of protein, legumes are particularly rich in this nutrient. It is important to consume adequate essential amino acids to meet dietary requirements. Soy contains all 9 essential amino acids in amounts that meet human needs and is a high quality, staple protein for vegetarians and vegans.⁶

A good rule of thumb for vegans is to consume 3-4 servings of legumes each day to ensure adequate intake of protein and the amino acid lysine, which is lacking in most other plant foods.⁷ One serving of legumes is equivalent to ½ cup cooked beans, peas and lentils, ½ cup tofu and tempeh, ¼ cup peanuts, or 2 tablespoons peanut butter.⁷Additional sources of plant-based protein include quinoa, seitan, whole grains, nuts, and seeds.⁷

Omega-3 Fatty Acids

Vegetarians and vegans need to be diligent about eating adequate alpha-linolenic acid (ALA).⁸ The body is capable of converting ALA to longer omega-3s eicosapentanoic acid (EPA) and docosahexanoic acid (DHA), although conversion rates can be quite low.

ALA-rich foods include soybean oil, walnuts, and ground flax, chia, and hemp seeds.⁹ To be prudent, vegetarians and vegans may take an algae-based DHA supplement in addition to eating a few daily servings of ALA-rich foods to meet omega-3 needs.¹⁰

Calcium and Vitamin D

While some dark leafy greens, such as collards and kale, contain calcium, most non-dairy vegetarians and vegans may need to consume calcium-fortified beverages and/or a calcium supplement to meet calcium needs. One cup cooked kale or collard, mustard or turnip greens provides approximately 200mg of calcium, about 20% of daily needs for adults.¹¹ One cup cooked edamame, ½ cup soynuts, ½ cup cooked tempeh, 2 tablespoons almond butter, and 1 cup cooked bok choy each deliver about 100mg of calcium.¹¹

Vitamin D needs may be met through fortified foods, dietary supplements, and sun exposure. Some UV-exposed mushrooms may contain vitamin D, but only if it is indicated on the label. It is a good idea for non-dairy vegetarians and vegans to consume calcium and vitamin D-fortified non-dairy plant milks.

Iron and Zinc

Menstruating individuals and endurance athletes have higher iron needs; thus, it is important to incorporate iron-rich foods into the diet daily.^12,13 Eating iron-rich plant foods with a source of vitamin C increases iron absorption. Plant foods that deliver iron include white beans, kidney beans, chickpeas, tofu, spinach, and Swiss chard.^12,13 Vitamin C-rich foods include citrus fruits, strawberries, kiwi, tomatoes, and bell peppers.¹⁴

Good plant sources of zinc include, oatmeal, wheat germ, pumpkin seeds, and cashews.¹⁵

Iodine

Iodine content of plant foods depends on the soil in which they’re grown. Non-dairy vegetarians and vegans can ensure adequate iodine intake by getting most of their sodium from iodized salt via home cooking and seasoning or by taking a supplement. Salt in processed foods is rarely, if ever, iodized.

Vitamin B12

Fortified foods and dietary supplements are the only reliable plant sources of vitamin B12.¹⁶ Recommendations in the book Vegan for Life by Jack Norris, RD, and Virginia Messina, MPH, RD, state vegans should do 1 of the following: consume 2 servings/day of fortified foods providing 1.5-2.5mcg of vitamin B12 each, take a daily vitamin B12 supplement of at least 25mcg, or take a supplement of 1,000mcg 2 times/week.¹⁶

REFERENCES

Plant Based Foods Association. Why Plant Based? https://plantbasedfoods.org/why-plant-based/. Accessed October 1, 2019.
The Vegetarian Resource Group. How Many Adults in the U.S. are Vegetarian and Vegan? https://www.vrg.org/nutshell/Polls/2016_adults_veg.htm. Accessed October 1, 2019.
United States Department of Agriculture. MyPlate. www.choosemyplate.gov. Accessed October 1, 2019.
Virginia Messina. The Plant Plate. https://www.theveganrd.com/vegan-nutrition-101/food-guide-for-vegans/. Accessed October 1, 2019.
Brenda Davis. The Vegan Plate. https://www.brendadavisrd.com/my-vegan-plate/. Published May 19, 2016. Accessed October 1, 2019.
Soy Connection. Soy Protein. https://www.soyconnection.com/foodindustry/soy-protein. Accessed October 1, 2019.
Jack Norris. Protein Part 1 – Basics. https://veganhealth.org/protein-part-1/. Updated January 2016. Accessed October 1, 2019.
Vegan Health. Omega-3s Part 2—Research. https://veganhealth.org/omega-3s-part-2/. Updated October 2018. Accessed October 1, 2019.
National Institutes of Health Office of Dietary Supplements. Omega-3 Fatty Acids Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/. Updated July 9, 2019. Accessed October 1, 2019.
Vegan Health. Daily Needs. https://veganhealth.org/daily-needs/#Omega-3-Fats. Accessed October 1, 2019.
Vegetarian Nutrition Dietetic Practice Group. Meeting Calcium Recommendations on a Vegan Diet. https://vegetariannutrition.net/docs/Calcium-Vegetarian-Nutrition.pdf. Published 2019. Accessed October 1, 2019.
National Institutes of Health Office of Dietary Supplements. Iron Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/. Updated August 22, 2019. Accessed October 1, 2019.
Vegetarian Nutrition Dietetic Practice Group. Iron in Vegetarian Diets. https://vegetariannutrition.net/docs/Iron-Vegetarian-Nutrition.pdf. Published 2018. Accessed October 1, 2019.
National Institutes of Health Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/. Updated September 18, 2018. Accessed October 1, 2019.
Vegetarian Nutrition Dietetic Practice Group. Zinc in Vegetarian Diets. https://vegetariannutrition.net/docs/Zinc-Vegetarian-Nutrition.pdf. Published 2019. Accessed October 1, 2019.
Norris J, Messina V. Vegan For Life. Cambridge, MA: Da Capo Press; 2011.