Vegan health and nutrition: questions answered with sources

A well-planned vegan diet can be healthy, says the British Dietetic Association, and a 2023 review found 21% less ischaemic heart disease in vegetarians. Vegans had more hip fractures in EPIC-Oxford, and death rates are mixed.

You don’t need meat to be healthy, say dietitians in five countries, if your diet is planned and includes B12. UK vegetarians died at about the same rate as meat-eaters (2016), though they and vegans break more hips.

Going vegan needn’t make you tired or weak if you eat enough and get B12, but plan for iron: across four studies, a 2021 review found 15% of vegans and 7% of meat-eaters iron deficient. See a GP if tiredness lasts weeks.

Needing B12 doesn’t single out a vegan diet as unnatural: the US Institute of Medicine advised in 1998 that everyone over 50 get most of their B12 from supplements or fortified food. Vegans need such a source at every age.

Vegan junk food is still junk food: in a 2017 study of over 200,000 US health workers, diets richest in whole plant foods had 25% less coronary heart disease than the poorest, and those richest in refined ones 32% more.

A vegan diet can meet protein needs when meals are built on pulses or soya: the UK reference, set in 1991, is 0.75 g per kilo a day, about 53 g at 70 kg. Older people, athletes and pregnant women should plan for more.

Athletes can be vegan: a 2025 meta-analysis of randomised trials found no significant strength gap between plant and animal protein, but less muscle with plant, more so with weight training. Plan protein, B12 and iron.

Vegans who eat enough protein build muscle much as meat-eaters do: in a 2021 trial, vegan and omnivorous novices on 1.6 g of protein per kilo a day gained the same leg muscle. Soy matches milk protein; others lag a little.

Vegans don’t need to combine proteins at every meal: in a 2024 US trial of nine women, 24-hour muscle protein synthesis did not differ whether beans and bread were eaten together or apart. Total protein is what to watch.

Vegan men had no less testosterone than meat-eaters in UK Biobank (Tong et al., 2021): 166 white British vegans averaged 11.7 nmol/l and regular meat-eaters 11.3, not a significant gap. Meat’s appeal to men looks partly cultural.

Vegans need B12 from fortified foods or a supplement: the Vegan Society advises at least 10 micrograms a day or 2,000 a week, as UK dietitians repeated in 2021. It matters most in pregnancy and while breastfeeding.

Calcium needn’t come from dairy, but vegans in EPIC-Oxford (2020) had a 43% higher fracture rate than meat-eaters, only partly explained by low calcium. Get at least 700 mg daily from fortified foods and calcium-set tofu.

Vegans can meet the choline target with soya, beans or a supplement, but it takes planning: Storz et al. (2025) found German vegans ate 257 mg a day and meat-eaters 329 mg, against EFSA’s 400 mg. Needs rise in pregnancy.

Vegans tend to eat at least as much iron as meat-eaters but store less: a 2021 review found ferritin averaged 31.3 µg/L in vegans, 55.5 in meat-eaters. Anaemia is also more common, especially in premenopausal women.

Vegans need omega-3 like anyone, and can get EPA and DHA from algae oil, where fish get theirs: a 2025 analysis of a randomised trial found it raised blood levels as well as fish oil, dose for dose.

Vegans average lower vitamin D than meat-eaters, and UK advice since 2016 asks everyone to consider 10 micrograms a day in autumn and winter. Take it as D2 or lichen D3, and all year if you have dark skin or get little sun.

Iodine is a weak spot for vegans: a 2023 review (Eveleigh et al.) found them lowest in all five studies measuring urinary iodine. UK dietitians suggest adults use iodine-fortified plant milk or a supplement of up to 150 µg daily.

Vegans have lower bone density on average and, in EPIC-Oxford (2020), 2.3 times meat-eaters’ hip fracture risk, about 15 more per 1,000 people over ten years. Lower weight, calcium and protein explain only part of it.

Zinc and selenium need planning on a vegan diet: two German studies (2023, 2025) found 7% to 40% of vegans with low blood selenium, against at most 2.5% of meat-eaters. A low-dose supplement is steadier than Brazil nuts.

Dietitians say a well-planned vegan diet can suit children, but a 2026 meta-analysis of 59 studies found vegan children shorter on average and more often short of B12. Paediatricians urge B12 supplements and monitoring.

Canadian, Irish and UK dietitians say a planned vegan diet can suit pregnancy and breastfeeding. Babies from vegan homes were about 100 g lighter at birth but grew much like others by two (Israel, 2026). Take B12.

A vegan diet can suit older people if planned: in a 2026 Dutch trial, over-65s who chose their own vegan food ate less protein and lost thigh muscle in 12 weeks. Vegans have more hip fractures, so bones need care too.

Processed meat causes bowel cancer and red meat probably does, the WHO’s cancer agency found in 2015. In UK data, 79 g a day of both meant 14 more bowel cancers per 10,000 people over about seven years than under 11 g.

A plant-based diet feeds the gut bacteria that ferment fibre, and UK adults average just 16.4 g of fibre a day against the 30 g advised (2025 survey). In one 2025 study, vegans’ gut bacteria were slightly less diverse.

Soy foods have not been found to raise breast cancer risk: in 300,852 women, the China Kadoorie Biobank (2020) saw no difference between the highest and lowest soy eaters. In survivors soy is linked to fewer recurrences.

No study shows that a vegan diet causes depression. Most meta-analyses find more depression in people who avoid meat, but Tan et al. (2026), tracking 77,678 people, found the link small and unlikely to be causal.

A vegetarian diet with lifestyle changes partly reversed heart disease in small studies: in Ornish’s 1998 trial, artery narrowing eased 3.1 points in five years, against 11.8 worse on usual care. Try it alongside your medicine.

A plant-based diet is linked to a lower risk of type 2 diabetes, 18% lower in a 2023 meta-analysis of observational studies, and in trials it modestly lowers blood sugar. On diabetes medicine? See your GP first.

Soy did not significantly change men’s testosterone or oestrogen in a 2021 meta-analysis of 41 clinical studies (Reed et al.). A few case reports tie heavy soy intake to breast growth or low testosterone.

Vegans can eat low-carb: in Eco-Atkins (2014), a lower-carb vegan diet cut LDL 0.49 mmol/L more than a high-carb vegetarian one, though half its group quit. Vegan keto is untested; on diabetes drugs, see a doctor first.

Lectins in properly cooked beans have no proven harm: cooking cut lectin activity in pulses by 94 to 99.8% in a 2018 Canadian study. Undercooked kidney beans can poison you, and phytate cuts iron and zinc absorption.

No evidence shows that eating for your blood type improves health: a 2013 systematic review screened 1,415 references and found no such study. Later studies found that matching a diet to blood group made no difference.

Vegans don’t need collagen or animal fat, as the body builds collagen from amino acids with vitamin C and iron. In EPIC-Oxford (2016), vegan men had 16% more glycine but 13% less lysine in their blood than meat-eaters.

A strict raw diet, vegan or not, carries real risks: in Germany’s Giessen Raw Food Study (1999), about 30% of women under 45 eating mostly raw had partly or fully lost their periods. Cooking makes many plant foods safer.

Gluten harms the roughly 1% with coeliac disease (0.8% by biopsy in a 2026 global review), and wheat can make those with a wheat allergy or sensitivity ill. For others, wholegrains are linked to better health.