Supplements for Vegetarians: Filling the Nutrition…

Vegetarianism encompasses a wide range of dietary patterns: lacto-ovo vegetarians who eat dairy and eggs, pescatarians who include fish, lacto-vegetarians who eat dairy but not eggs, and ovo-vegetarians who eat eggs but not dairy. Each variation creates a different nutritional profile with different potential gaps. Unlike veganism, most vegetarian diets include at least some animal products, which covers certain critical nutrients. But several gaps are common across most vegetarian dietary patterns and deserve systematic attention.

Vitamin B12: Still a Priority for Many Vegetarians

Unlike vegans, many vegetarians consume dairy and eggs — both of which contain B12. The question is whether these sources provide enough. The answer varies considerably by individual.

Dairy products provide B12, but in amounts that require meaningful consumption to meet the RDA of 2.4 mcg per day: about 1.1 mcg per cup of milk, 1.1 mcg per cup of yogurt, and up to 0.9 mcg per ounce of some cheeses. Two cups of dairy-based foods and an egg per day will meet the RDA for most people.

The complication is absorption. B12 absorption requires intrinsic factor (produced by stomach cells) and sufficient stomach acid. After age 50, a significant percentage of people develop atrophic gastritis, which reduces intrinsic factor and stomach acid production, impairing B12 absorption from food. For older vegetarians, B12 supplementation or testing is genuinely important regardless of dairy and egg intake.

Additionally, some vegetarians eat minimal dairy due to lactose intolerance or personal preference. These individuals should treat B12 similarly to vegans — testing and supplementing as needed.

Omega-3 EPA and DHA

Lacto-ovo vegetarians do not eat fish, removing the primary dietary source of EPA and DHA. While eggs contain small amounts of DHA (especially omega-3 enriched eggs from hens fed flaxseed or algae), the amounts are generally insufficient to maintain optimal tissue levels without fish.

The ALA-to-EPA/DHA conversion problem applies equally to vegetarians as to vegans. Plant-based omega-3s from flaxseed, chia, and walnuts are primarily ALA and convert poorly. Algae oil supplements providing 200-500 mg DHA per day are the evidence-based solution for non-fish-eating vegetarians.

Iron: Particularly Important for Women

As with vegans, vegetarians consume only non-heme iron. The absence of heme iron and the meat factor (which enhances non-heme iron absorption) means vegetarian diets are structurally less efficient for iron delivery.

Women of reproductive age who are vegetarian face the greatest risk. Menstruation increases iron demands, and the lower absorption efficiency of plant iron means dietary iron must be substantially higher to meet actual needs. Consuming vitamin C with every iron-rich meal, avoiding coffee and tea around mealtime, and testing ferritin periodically are the most important strategies. Iron supplementation should be targeted based on lab values rather than taken universally.

Zinc

The same phytate issue affecting vegans applies to vegetarians. Dairy and eggs provide some zinc (about 1 mg per egg, varying amounts in cheese), but diets heavy in whole grains and legumes without regular zinc-rich animal products may still fall short on absorbed zinc.

Regularly including eggs, dairy, pumpkin seeds, and hemp seeds, while using preparation techniques that reduce phytate content, helps. If dietary intake is inconsistent, 8-12 mg of supplemental zinc per day fills the gap.

Vitamin D

Vitamin D status is an issue across all dietary patterns, not uniquely vegetarian. Egg yolks contribute about 40-50 IU per egg, and some dairy products are fortified. In the absence of substantial sun exposure, most vegetarians benefit from 1,000-2,000 IU of supplemental vitamin D3 daily.

Vegetarians who eat dairy can often find vitamin D3 supplements derived from lanolin; those who prefer vegan sources should look for lichen-derived D3.

Iodine

Iodine is well-supplied in dairy products (cows are often given iodine supplements, and iodine-containing sanitizers used in dairy operations add to the iodine content of milk). Vegetarians who consume dairy regularly typically have adequate iodine. Those who minimize dairy and do not use iodized salt should consider a supplement of 150 mcg per day.

Eggs provide a small amount of iodine (about 25 mcg per egg) and contribute modestly to overall intake.

What Vegetarian Diets Do Well

It is worth acknowledging what vegetarian diets typically provide abundantly: folate from legumes and leafy greens, vitamin C from fruits and vegetables, magnesium from nuts, seeds, and legumes, potassium from produce, fiber for gut health, and antioxidant polyphenols from plant diversity.

Vegetarians generally show lower rates of heart disease, type 2 diabetes, and certain cancers in observational studies, effects that persist after controlling for other lifestyle factors. These benefits come from the overall dietary pattern, not from supplementation.

FAQ

Q: Should all vegetarians take a multivitamin?

A targeted approach based on individual dietary patterns is more effective than relying on a multivitamin to cover everything. Most multivitamins contain suboptimal forms and doses of key nutrients (e.g., magnesium oxide instead of glycinate, low vitamin D). Specific supplementation of the nutrients most likely to be deficient for your particular diet is preferable.

Q: Is pescatarian diet significantly different from lacto-ovo vegetarian nutritionally?

Yes. Pescatarians who eat fish regularly get well-absorbed EPA and DHA, heme iron from shellfish, zinc from oysters, and additional iodine and selenium from seafood. The supplement needs of a pescatarian are much closer to an omnivore than to a standard lacto-ovo vegetarian.

Q: Do vegetarians need to worry about carnitine?

L-carnitine is found primarily in red meat and is synthesized by the body from lysine and methionine (amino acids present in both plant and animal foods). Vegetarians may have lower plasma carnitine levels but deficiency is uncommon in healthy adults. Athletic vegetarians doing high-volume endurance training might consider L-carnitine supplementation for potential performance benefits, though evidence is mixed.

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Supplements for Vegetarians: Filling the Nutritional Gaps