The Evidence
The Evidence
Vegan nutrition, answered from the primary sources: government fact sheets, professional-body position papers, and peer-reviewed studies, every one linked. A summary of the cited evidence, not medical advice.
This is a summary of the cited evidence, not medical advice. Evidence last reviewed July 18, 2026.
The nutrients
- 01 Start here Strong evidence
Vitamin B12 on a vegan diet
This is the one nutrient the evidence is blunt about: plant foods are not a reliable source, so vegans need a supplement or fortified foods. Full stop.
- 02 Settled
Protein on a vegan diet
The 'where do you get your protein' question has a boring, well-documented answer: from plants, across the day, and the complete-versus-incomplete framing was retired years ago.
- 03 Strong evidence
Iron on a vegan diet
Plants have iron, just the kind your body absorbs less easily. The government fact sheet quantifies exactly how much less, and what raises the odds in your favor.
- 04 Strong evidence
Omega-3s on a vegan diet
Flax and walnuts give you the parent omega-3. Turning it into the ones your brain and heart use is inefficient, which is where algae oil comes in.
- 05 Mixed
Calcium and bone health on a vegan diet
This is the page where being on veganism's side means telling you the uncomfortable finding: vegans break more bones in the data, and calcium is the lever that moves it.
- 06 Strong evidence
Vitamin D on a vegan diet
Vitamin D is the one almost everyone runs low on in winter, vegan or not. The plant-friendly fix is D2 or lichen D3, plus fortified foods and sensible sun.
- 07 Strong evidence
Iodine on a vegan diet
Iodine is the quiet one: no drama, easy to miss, easy to fix. Iodized salt or a measured amount of seaweed does it, and kelp can overshoot hard.
- 08 Strong evidence
Zinc on a vegan diet
Plants have zinc; phytates make you absorb less of it. The fix is more intake plus a few kitchen tricks that free the zinc up.
- 21 Strong evidence
Creatine on a vegan diet
Your body makes some creatine, and the only foods that carry the rest are meat and fish. That leaves vegans with lower stores, which may be exactly why they respond so well to the supplement.
- 22 Mixed
Choline on a vegan diet
Choline is the nutrient nobody talks about until pregnancy, and the richest sources are animal foods. The plant list is real but shorter, and most people of any diet already fall short.
- 23 Strong evidence
Selenium on a vegan diet
Selenium is the mineral your food inherits from the dirt it grew in. That makes plant levels a lottery of geography, and it is why vegan intakes can run low, and why two Brazil nuts can flip the whole thing.
- 24 Strong evidence
Vitamin A on a vegan diet
Vegans get vitamin A the long way round: plants supply beta-carotene, and the body turns it into the active vitamin. The conversion is real but not identical in everyone, which is why the orange and dark-green vegetables earn their place.
- 25 Mixed
Riboflavin (B2) on a vegan diet
Riboflavin is a quiet one: no dramatic deficiency story, just the fact that dairy and eggs carry a lot of it. Take those away and the NIH puts vegans on the watch list, which fortified foods and a few staples handle.
- 26 Strong evidence
Vitamin K and K2 on a vegan diet
Vitamin K1 is one of the easiest nutrients to get on a plant diet: it is what makes leafy greens green. K2 is the one people worry about, and the honest answer involves natto, gut bacteria, and your own biology.
- 27 Myth
The protein combining myth
The old rule was that vegans had to pair rice with beans at every meal to make a complete protein. The people who write the position papers say that was never true.
- 32 Strong evidence
Magnesium on a vegan diet
Magnesium is one of the easier minerals to get on a plant diet, because its best sources are exactly the foods a good vegan diet is built on.
- 33 Strong evidence
Potassium on a vegan diet
Potassium is the mineral the modern diet is short on, and plant-based eating is where it is easiest to get. Fruit, vegetables, beans and potatoes are all loaded with it.
- 34 Strong evidence
Folate on a vegan diet
Folate is the one B vitamin plant eaters rarely have to think about. The name comes from foliage, and the diet is built on exactly that.
- 35 Strong evidence
Copper on a vegan diet
Copper is a trace mineral few people think about, and plant eaters have little reason to worry. Nuts, seeds and whole grains carry it well.
Health outcomes
- 09 Strong evidence
Plant-based diets and heart disease
The heart-disease evidence is genuinely good for plant-based eating, and honest reporting includes the one finding that cut the other way: stroke.
- 10 Myth
Does soy mess with your hormones?
The soy-wrecks-your-hormones story is one of the most repeated food myths going, and the review evidence just does not support it.
- 11 Settled
Processed meat and cancer: what IARC actually found
Group 1 carcinogen sounds like bacon equals cigarettes. That is not what it means, and the real finding is both more modest and more solid than the headlines.
- 12 Strong evidence
Vegan diets in pregnancy and childhood
This is the page to get right, so it is the page with the most hedging. The dietitians' body says a planned vegan diet works at every life stage. The same sources say B12 is not optional.
- 13 Strong evidence
Plant-based diets and type 2 diabetes
Vegetarians and vegans get type 2 diabetes far less often, and a vegan diet helps manage it, though the trial effect on blood sugar is real and modest, not a cure.
- 14 Strong evidence
Plant-based diets and blood pressure
Plant-based eating lowers blood pressure by a few millimetres of mercury, small for one person but the kind of shift that moves population risk.
- 15 Mixed
Plant-based diets and longevity
One large cohort found vegetarians die at lower rates; another found no difference. The honest answer on longevity is that the evidence is split.
- 16 Mixed
Plant-based diets and cancer risk
Going plant-based nudges cancer risk down, mostly through what you stop eating. The overall effect is real, modest, and easy to oversell in either direction.
- 17 Strong evidence
Plant-based diets, gout and kidney stones
For gout and kidney stones, cutting meat is one of the cleaner wins in nutrition. Vegetarians formed about a third fewer stones, and plant purines never earned their bad reputation.
- 18 Strong evidence
Plant-based diets, bone health and fracture risk
Publishing the unflattering finding is the point: in the best cohort, vegans broke more bones. The risk is real, it mostly tracks calcium, protein and body weight, and it is fixable.
- 28 Strong evidence
Vegan diets and athletic performance
A growing list of pro athletes eat plant-based, and the science is not the obstacle it was once assumed to be. The position papers put vegan diets squarely inside the range that works for sport.
- 29 Strong evidence
Plant-based diets and weight
Across tens of thousands of people, the pattern is consistent: the more plant-based the diet, the lower the average body weight. It is one of the better-supported claims in the whole field.
- 30 Strong evidence
Plant-based diets and cholesterol
If a diet has one signature effect on the blood, for plant-based eating it is cholesterol. Low saturated fat plus high fibre pushes LDL down, and the trials back it up.
- 31 Strong evidence
Fibre on a vegan diet
Fibre is the nutrient almost everyone under-eats, and it is the one plant-based diets deliver in abundance. Vegans eat the most of anyone, and the payoff shows up across the body.
The industry record
- 19 Emerging
Cultivated meat approval timeline
Not opinion, a ledger. Every US cultivated-meat milestone below is a public government document with a date and a link. Here is what has actually cleared regulators, and when.
- 20 Settled
The climate case for eating plants
Food is roughly a quarter of the emissions warming the planet, and the single biggest lever an individual has is what goes on the plate, not how far it traveled.
How these pages are built
Nutrition is the one topic where a confident tone and a wrong fact do real harm, so on these pages the sources do the talking. Every quote is a word-for-word copy from a named primary source: NIH Office of Dietary Supplements fact sheets, which are US government public-domain documents, the Academy of Nutrition and Dietetics position paper, the EPIC-Oxford and Adventist Health Study 2 cohorts, and the FDA and USDA records behind cultivated meat. Every quotation is checked against the archived source text before the page can publish, so what you read is exactly what the source wrote.
Where the evidence is genuinely good, we say so. Where it cuts against the flattering story, like the higher fracture and stroke findings, we quote that too. Being on veganism's side means holding the case to the honest standard, not the convenient one.
Wondering whether a specific ingredient makes the cut, from carmine to bone-char sugar? That is the job of our companion shelf, Is it vegan?, where each additive gets a plain verdict and the primary source behind it.
Evidence first, every morning.
The standard behind these pages, applied to each day’s news: the study quoted and graded before the headline reaches you. One short brief, free.
Free, every morning. No guilt. No preaching.