Vegan diets can be healthy for adults, and B12 is not optional

Key takeaways

• In 2025, the Academy of Nutrition and Dietetics said well-planned vegetarian and vegan diets can meet adults’ needs, but its position does not cover pregnancy or anyone under 18¹.
• Germany’s national nutrition society now calls vegan eating health-promoting for healthy adults, as long as they plan meals well and take a vitamin B12 supplement².
• In three U.S. studies of more than 200,000 adults, plant-based diets built on whole foods tracked with 25% less heart disease, while plant diets heavy in sweets, refined grains and sugary drinks tracked with 32% more⁵.
• British vegans had 2.3 times the hip fracture risk of meat eaters, so calcium, vitamin D and protein deserve the same attention as B12⁴.
• Plant foods contain no B12 unless it has been added, so every vegan needs fortified foods or a supplement⁹.

Between May and July 2022, Stanford researchers split 22 pairs of identical twins at the dinner table. One twin in each pair ate a vegan diet for eight weeks. The other ate a diet that included chicken, fish, eggs and dairy. Both menus were healthy, heavy on vegetables, beans and whole grains, with no sugary foods or refined starches⁶.

Because twins share their genes, the design isolates diet better than most studies can.

The vegan twins’ LDL cholesterol, the kind linked to clogged arteries, fell from about 111 to about 96 mg/dL. Their meat-eating siblings went from about 119 to about 116⁶. On the vegan side, fasting insulin dropped about 20%, and those twins ended up about 4 pounds lighter than their siblings⁶.

Yet the study’s senior author, Stanford’s Christopher Gardner, didn’t tell everyone to go vegan. He said eating more plant foods matters more than going strictly vegan⁶.

Eight weeks can’t answer the questions that matter over decades, such as whether your bones stay strong. This guide weighs both sides and ends with a nutrient checklist for your next checkup.

Two expert groups now back vegan eating for adults, with conditions

The Academy of Nutrition and Dietetics, the professional group for registered dietitians, approved a new position in January 2025. It says “appropriately planned vegetarian and vegan dietary patterns can be nutritionally adequate” for adults and may help with heart and metabolic disease¹. The position stays in effect through 2032¹.

Its limits matter, too. The paper covers only adults who aren’t pregnant or breastfeeding. Children, teens and pregnancy are outside its scope¹. The authors also rated much of the evidence on specific diseases as low or very low quality¹.

Germany’s national nutrition society, the DGE, moved further. In 2016, it said vegans could hardly get enough nutrients without supplements, and it advised against vegan diets for pregnant and breastfeeding women, children and teens².

Its 2024 update says a vegan diet can be health-promoting for healthy adults under three conditions: a B12 supplement, well-planned meals, and enough of the other nutrients that tend to run short². For children, teens, pregnant and breastfeeding women, and older people, the DGE now makes no clear recommendation either way².

A whole-food vegan diet and a junk-food vegan diet are different diets

French fries, soda and white bread are all vegan. So researchers began asking which plant foods people eat, not just whether they skip animal foods.

A team led by Ambika Satija followed more than 200,000 nurses and health professionals in three long-running American studies, some for nearly three decades⁵. They scored diets two ways. A healthful plant-based score rewarded whole grains, fruits, vegetables, nuts, legumes, plant oils, tea and coffee. An unhealthful score rewarded juices, sweetened drinks, refined grains, potatoes, fries and sweets⁵.

People with the highest healthful scores had 25% less coronary heart disease than those with the lowest. People with the highest unhealthful scores had 32% more⁵. A simple “more plants, fewer animal foods” score showed only a small, borderline drop of 8%⁵. These were observational findings about plant-leaning diets, not strict vegan ones, so they show patterns, not proof.

Plant-based meats sit in between. In the 2020 SWAP-MEAT trial, Stanford researchers had 36 healthy adults spend eight weeks eating two or more daily servings of Beyond Meat products and another eight weeks eating animal meat, mostly red meat⁷.

During the plant-based phase, LDL cholesterol fell an average of 10 mg/dL and weight dropped about 2 pounds⁷. Levels of TMAO, a gut-bacteria byproduct studied as a heart risk marker, were also lower. Gardner, who led the trial, said no one can yet be sure TMAO causes heart disease⁷.

Apply the same skepticism you’d bring to a meat-industry study. Beyond Meat paid for the trial through a research gift, though the company had no role in its design or analysis⁷⁸. Food-policy scholar Marion Nestle noted that the rest of participants’ diets wasn’t controlled and that the products are ultraprocessed. She said any health benefit from swapping them for meat needs independent confirmation⁸.

The Academy’s view is measured. Plant-based meats and milks are ultraprocessed, and some carry plenty of sodium and saturated fat. Yet they haven’t been tied to the harms seen with foods like soda, and they tend to offer more fiber and less saturated fat than animal foods¹. Our article on ultra-processed food covers that debate.

Hearts tend to do better, and bones and strokes need watching

Some of the longest-running data come from EPIC-Oxford, a British study that recruited many people who don’t eat meat. Researchers followed 48,188 adults for about 18 years³.

Compared with meat eaters, vegetarians, a group that included vegans, had 22% less ischemic heart disease, the kind caused by narrowed arteries³. They also had 20% more strokes, mostly the bleeding kind, called hemorrhagic strokes³.

That’s about 10 fewer cases of heart disease and 3 more strokes for every 1,000 people over 10 years³. The heart advantage shrank once the researchers accounted for cholesterol, blood pressure, diabetes and body weight, which suggests those factors explain part of it³.

Bones are the clearer warning for vegans. In a later EPIC-Oxford analysis, vegans had 43% more fractures overall than meat eaters and 2.31 times the risk of hip fracture⁴. That works out to about 15 more hip fractures per 1,000 people over 10 years⁴.

Lower body weight explained part of the gap. Lower calcium and protein intake explained a little more, but not all of it⁴.

The fix may be within reach. In one study cited by the Academy, vegan women who took calcium and vitamin D supplements had about the same hip fracture risk as nonvegetarians. Vegan women who didn’t take them had almost three times the risk¹.

The DGE’s 2024 review of many studies points the same way. Vegan diets were linked to lower heart disease and cancer risk and to higher fracture risk, but its reviewers rated all three findings low or very low in certainty². The firmest result came from eight randomized trials: vegan diets produced about 2.5 kilograms (5.5 pounds) more weight loss than comparison diets, a finding rated moderate in certainty².

B12 is the one nutrient plants can’t supply

The NIH Office of Dietary Supplements (ODS) is blunt: only animal foods contain vitamin B12 naturally, and plant foods have none unless it has been added⁹. Some cereals, nutritional yeasts and other products are fortified. The Nutrition Facts label tells you which ones⁹.

Adults need 2.4 micrograms (mcg) a day. The amount rises to 2.6 mcg in pregnancy and 2.8 mcg while breastfeeding⁹.

B12 helps make red blood cells and keeps nerves working. A shortfall can cause fatigue, numbness or tingling in the hands and feet, balance problems, depression and memory trouble⁹. Nerve damage can happen even before anemia shows up, which is why ODS says treatment should start quickly⁹.

Vegans have the lowest B12 levels and the highest deficiency rates of any diet group, the Academy reports. It calls supplements potentially “the easiest and most reliable way” to stay covered¹.

You don’t need a fancy form. Cyanocobalamin, the most common kind in supplements, holds its own: ODS says research has yet to show that methylcobalamin or any other form does a better job⁹. High-dose pills of 500 or 1,000 mcg are considered safe, ODS adds, even though most of each dose never gets absorbed⁹. If you also take metformin or an acid reducer, ask about your B12, because both can lower it⁹.

A vegan nutrient checklist for your next checkup

B12 comes first, but it isn’t alone. The DGE lists omega-3 fats, vitamin D, calcium, zinc, iodine and, for women, iron as nutrients vegans may run short on². The Academy adds choline to the watch list¹.

Nutrient	Why vegans plan for it	Plant or fortified sources	When a supplement makes sense	What to ask your clinician
Vitamin B12	Only animal foods supply it naturally9	Fortified cereals, nutritional yeast and other fortified foods; check labels9	Always: the DGE makes it a condition of vegan eating, and the Academy calls supplements possibly the most reliable route12	A blood B12 check, especially with tingling, fatigue or metformin9
Iodine	Vegans are a named risk group10	Iodized salt; sea, kosher and Himalayan salts usually aren’t iodized10	If you skip iodized salt; 150 mcg a day if pregnant or breastfeeding, per the American Thyroid Association10	Whether your prenatal vitamin has iodine; only about half do10
Vitamin D	Vegans run lower, especially in winter1	Fortified plant milks (often about 3 mcg per cup, like cow’s milk), UV-treated mushrooms12	When sun and fortified foods fall short; adult goal 15 mcg (600 IU), upper limit 100 mcg (4,000 IU)12	Whether to check your level if you get little sun or have darker skin12
Calcium	Vegans eat much less than vegetarians1	Tofu made with calcium, fortified soy and almond drinks, kale, broccoli, bok choy11	If you can’t eat 2 to 3 calcium-rich servings a day; take 500 mg or less at a time111	Your fracture risk and bone health4
Iron	Plant iron absorbs less well than iron from meat13	Beans, lentils, spinach, peas, fortified cereal, paired with vitamin C foods13	If a clinician finds you’re low; don’t top 45 mg a day without advice13	Iron levels if you have heavy periods or are pregnant13
Zinc	Phytates in beans, grains and seeds block some absorption15	Beans, lentils, chickpeas, pumpkin seeds, cashews, oatmeal; tempeh and miso help absorption15	Rarely; don’t go above 40 mg a day15	Testing only if you have symptoms15
Omega-3 DHA and EPA	Low or absent without a supplement1	Flaxseed, chia, walnuts, canola oil supply ALA, which the body converts only a little14	Algae-based oil is an option, though experts say it may not be required114	Whether algal oil fits your health goals
Protein	Needs may rise with age1	Beans, lentils, tofu, tempeh, nuts, seeds	Food usually covers it	Your target; older adults need at least 1 gram per kilogram of body weight1

Keep iron pills away from children, because accidental iron overdose is a leading cause of fatal poisoning in kids under 6¹³. And go easy on kelp: the Academy warns that brown seaweeds can deliver too much iodine¹. The adult upper limit is 1,100 mcg a day¹⁰.

For protein amounts and plant protein quality, see our protein guide.

Pregnancy, children and older adults are where experts part ways

The evidence for these groups is thinner, and the stakes are higher.

The Academy’s 2025 position doesn’t cover pregnancy or anyone under 18¹. The DGE says data are too limited for a clear yes or no. It warns that a poorly run vegan diet in these groups can have effects that may not be reversible, and it strongly advises guidance from a qualified nutrition professional².

Some risks are specific. Babies of vegan mothers who are pregnant or breastfeeding may not get enough B12⁹. In infants, a shortfall can show up as poor growth and delayed development⁹.

Pregnant women need about 50% more iodine than other women, yet only about half of U.S. prenatal vitamins contain any¹⁰.

Older vegans have their own list. People over 50 absorb B12 better from supplements and fortified foods than from food sources⁹. Women over 50 and everyone over 70 need 1,200 mg of calcium a day¹¹. Adults over 70 need 20 mcg (800 IU) of vitamin D¹².

Talk with your clinician before a big diet change if you’re pregnant or take medicine for diabetes or blood pressure. A new way of eating can shift your numbers, and your doses may need to follow. Our article on healthy habits that clash with medicines explains how to plan that conversation.

A supplement protects the values behind a vegan plate

Many people choose vegan eating for reasons that run deep: care for animals, concern for the planet, a wish to eat close to the earth. A whole-food version lines up with what natural-health readers already prize. Think beans, whole grains, vegetables, nuts and seeds, cooked at home.

The research rewards that version, not the vegan label itself⁵. It also shows that a B12 pill isn’t a sign the diet failed. It’s a small, known fix for one gap that plants can’t fill. And a plant burger is still a factory product, judged by the same standard as any other.

What the evidence shows

Claim	Evidence rating	What it rests on
Vegans need a reliable B12 source	Strong evidence	Only animal foods supply it; vegans have the highest deficiency rates19
Well-planned vegan diets can meet adults’ needs	Strong evidence	Nutrient research reviewed by U.S. and German expert groups in 2024 and 2025, both conditional on planning and B1212
Vegan diets help with weight loss	Promising but early	Eight randomized trials show about 2.5 kg more loss, rated moderate certainty2
Vegetarian and vegan diets lower heart disease risk over decades	Promising but early	Large observational studies; low to very low certainty in the DGE review23
Whole-food plant diets beat refined plant diets for the heart	Promising but early	Over 200,000 adults followed for decades; observational5
Vegans who run low on calcium and vitamin D break more bones	Promising but early	Consistent cohort findings of low certainty124
Plant-based meats improve heart risk factors versus red meat	Promising but early	One 36-person trial funded by the manufacturer78
Methylcobalamin works better than cyanocobalamin	Not enough evidence	No form has been shown superior9
Unfortified plant foods can cover your B12	Evidence says no, or unsafe	Plant foods have no B12 unless added9

Questions readers ask

The bottom line

A vegan diet built on whole plant foods can be healthy for adults, and two major expert groups now say so. Most of its benefits rest on observational studies and short trials, so treat them as promising rather than proven.

The non-negotiables are simple: a reliable B12 source every day, plus a plan for iodine, calcium, vitamin D and the rest of the checklist. If you’re pregnant, raising a vegan child, or taking medicine for diabetes or blood pressure, bring a clinician into the plan.

Related reading

• Who needs the new protein goal of up to twice the RDA
• Shortfalls in vitamins and minerals are common, but true deficiencies are not
• Some healthy habits clash with your medicines, so check these goals first
• The case against ultra-processed food keeps growing, though defining it is harder
• Fish eaters fared best in a big U.S. study of vegetarian eating

Sources

1. Raj S, Guest NS, Landry MJ, Mangels AR, Pawlak R, Rozga M. “Vegetarian Dietary Patterns for Adults: A Position Paper of the Academy of Nutrition and Dietetics.” Journal of the Academy of Nutrition and Dietetics, 2025. andeal.org
2. Klug A, Barbaresko J, Alexy U, et al., for the German Nutrition Society (DGE). “Update of the DGE position on vegan diet.” Ernährungs Umschau, 2024;71(7):60–84 (long version, in German; English summary at ernaehrungs-umschau.de). publications.pik-potsdam.de
3. Tong TYN, Appleby PN, Bradbury KE, et al. “Risks of ischaemic heart disease and stroke in meat eaters, fish eaters, and vegetarians over 18 years of follow-up: results from the prospective EPIC-Oxford study.” BMJ, 2019;366:l4897 (abstract via University of Oxford). leap.ox.ac.uk
4. Tong T, Appleby PN, Armstrong MEG, et al. “Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study.” BMC Medicine, 2020;18:353 (abstract via University of Bristol). research-information.bris.ac.uk
5. Satija A, Bhupathiraju SN, Spiegelman D, et al. “Healthful and Unhealthful Plant-Based Diets and the Risk of Coronary Heart Disease in U.S. Adults.” Journal of the American College of Cardiology, July 2017 (abstract reproduced by NATAP). natap.org
6. Stanford Medicine. “Vegan diet improves cardiovascular health, Stanford Medicine study of identical twins finds” (on Landry MJ, et al., JAMA Network Open, 2023;6(11):e2344457). ScienceDaily, November 30, 2023. sciencedaily.com
7. FoodNavigator. “Study: Plant-based meat alternatives improve cardiovascular risk factors compared with animal meat” (on Crimarco A, et al., SWAP-MEAT, American Journal of Clinical Nutrition, 2020). August 13, 2020. foodnavigator.com
8. Nestle M. “Industry-funded study of the week: Beyond Meat.” Food Politics, August 2020. foodpolitics.com
9. NIH Office of Dietary Supplements. “Vitamin B12: Fact Sheet for Consumers.” Updated December 15, 2023. ods.od.nih.gov
10. NIH Office of Dietary Supplements. “Iodine: Fact Sheet for Consumers.” Updated July 28, 2022. ods.od.nih.gov
11. NIH Office of Dietary Supplements. “Calcium: Fact Sheet for Consumers.” Updated September 14, 2023. ods.od.nih.gov
12. NIH Office of Dietary Supplements. “Vitamin D: Fact Sheet for Consumers.” Updated November 8, 2022. ods.od.nih.gov
13. NIH Office of Dietary Supplements. “Iron: Fact Sheet for Consumers.” Updated August 17, 2023. ods.od.nih.gov
14. NIH Office of Dietary Supplements. “Omega-3 Fatty Acids: Fact Sheet for Consumers.” Updated July 18, 2022. ods.od.nih.gov
15. Vegetarian Nutrition Dietetic Practice Group, Academy of Nutrition and Dietetics. “Zinc” consumer handout, by Jack Norris, RD, updated by Lauren Panoff, MPH, RD, 2020. phipps.conservatory.org