If you look at all types of vegetarian diets as a group, and all research studies of these diets, vitamin B12 is the nutrient most likely to be deficient in this type of eating plan. Adequate B12 intake can be and is a genuine concern if a relatively strict vegetarian diet is sub-optimal in quality. In the National Health and Nutrition Examination Survey (NHANES) data from 2003-2010, 55% of participants who described themselves as vegetarian had adequate B12 intake, in comparison with 82% of individuals who described themselves as non-vegetarians.
We would also be quick to add here, however, that B12 is a nutrient needed in very small amounts. Our daily recommended intake level at HealthyFood is only 2.4 micrograms per day. Since 3.2 ounces of sardines can provide you with 8.11 micrograms of B12, we are talking about two servings of sardines per week as a way of covering over 95% of your B12 needs. Our B12 nutrient profile will give you more ideas for covering your B12 needs if you are following a vegetarian-type meal plan. We've seen numerous studies of lacto-ovo and pesco-vegetarians that show adequate B12 intake. For more information on B12 and vegetarian diets, see our Q & A, "Is vitamin B12 really a problem in a vegetarian diet?"
After vitamin B12, the group of nutrients most likely to be deficient in a vegetarian meal plan are protein, vitamins B3 and B6, zinc, and selenium. For some practical suggestions here, let's take each of these nutrients in order.
- Protein: We've got to give a special nod to soybeans here. They are the only plant food on our website to rank in the Protein Top 10 at over 28 grams in one cup cooked. (Tofu also ranks as a very good source at about 18 grams in 4 ounces.) In the case of soybeans, we are talking about over half of our recommended daily protein amount in one cup. A one-cup serving of any HealthyFood bean/legume, however, can provide you with approximately 15 grams of protein—still 30% of our recommended daily amount in a single serving. The bottom line here: beans/legumes are a great way to boost your protein intake if you are vegetarian and not planning to consume any seafood or dairy/eggs.
- Vitamin B3: Ample intake of this nutrient can also be challenging on a vegetarian diet. Six of our top seven website foods for B3 are animal foods (tuna, chicken, turkey, salmon, beef, and lamb). The one plant-food exception is crimini mushrooms, which could provide 17% of your daily B3 needs per cup. In general, mushrooms are a good plant food to turn to if you are trying to improve your intake of B3. However, that being said, we would also note that many plant foods on our website can provide you with smaller amounts of B3 in the 2-3 milligram range, and so a half dozen of these foods over the course of your day can usually bump up your B3 to our daily recommended level of 16 milligrams. Your best plant food choices here are as follows: peanuts, brown rice, sweet potato, sunflower seeds, barley, green peas, and potatoes.
- Vitamin B6: Overall diet quality is especially important here, and it is relatively difficult to have a B6 deficiency on a high-quality vegetarian diet. There are simply too many plant foods in the fruit and vegetable food groups that provide at least 15% of our recommended daily amount for B6 (1.7 milligrams). Among fruits, your best bets are bananas. Among vegetables, the best sources are cruciferous vegetables (and especially cabbage), spinach, bell peppers and garlic. See our Vitamin B6 nutrient profile to learn about nearly half of our HealthyFood that rank as good, very good, or excellent sources of B6.
- Zinc: In the National Health and Nutrition Examination Survey (NHANES) data from 2003-2010, 46% of participants who described themselves as vegetarian had adequate zinc intake, in comparison with 72% of individuals who described themselves as non-vegetarians. So as you can see, adequate intake of this mineral can be challenging on a vegetarian meal plan. However, specific plant foods have fairly high concentrations of zinc, and five of our plant foods can provide you with 20% or more of our daily recommended amount (11 milligrams). Those foods are sesame seeds, pumpkins seeds, garbanzo beans, lentils, and cashews. Quinoa, tofu, and green peas fall one tier lower at about 10-15%.
- Selenium: Our top five HealthyFood for selenium all belong to the seafood group, and among our Top 15 foods for selenium, 10 are animal foods or seafood. So you can see how some specific choices might be needed to assure our daily recommended amount for selenium of 55 micrograms. Fortunately, you can get over 40% of your selenium from one cooked cup of barley, and over 33% from 4 ounces of tofu, 1 cup of brown rice, 1/4 cup of sunflower seeds, 1 cup of crimini mushrooms, or 1/2 cup of shiitake mushrooms.
From our perspective at HealthyFood, all of the nutrient deficiency risks associated with vegetarian diets in research studies (with the possible exception of vitamin B12) can be successfully avoided in all types of vegetarian diets provided that those diets are balanced and of high-quality.
More Information on Vegetarian Diets
For more information on the subject of vegetarian diets, please see our overview article "A Practical Look at Vegetarian Diets" as well as the following Q+As.
To see the research articles we reviewed in the writing of these articles, see here.