Close every nutritional gap in a plant-based diet — without the guesswork
A well-planned vegan diet is one of the healthiest ways to eat. An unplanned one creates deficiencies so subtle they take years to surface — and by then, the damage is done. Vegan Vitamins is the definitive guide to nutritional gaps specific to plant-based eating: B12, D3, omega-3s, iron, zinc, calcium, and iodine. For each nutrient, the guide covers why it's deficient in plant-based diets, what the deficiency looks like clinically and subclinically, which plant foods offer meaningful amounts, and when supplementation is necessary versus optional. Written for both new and long-term vegans, the guide includes a supplement stack by life stage (children, adults, pregnant, seniors), a lab test checklist to assess your current status, and a decision tree for choosing between the dozens of supplement formulations on the market.
B12 is the most discussed nutrient in vegan nutrition — and also the most misunderstood. The standard advice is simple: supplement with B12. But "supplement with B12" glosses over several questions that actually matter.
First, there are three forms of B12 in common supplements: cyanocobalamin, methylcobalamin, and adenosylcobalamin. Cyanocobalamin is the cheapest and most studied, but requires conversion before use. Methylcobalamin is more bioavailable for some people but degrades faster in storage. The difference matters if you're already deficient — absorption varies significantly depending on your MTHFR genetic variant.
Second, dosing frequency changes the math entirely. The gut's intrinsic factor mechanism — which binds B12 for absorption — saturates at approximately 2mcg per meal. Once saturated, only about 1% of additional B12 is absorbed passively. This means a daily 500mcg supplement is not equivalent to 250 doses of 2mcg — and it also means weekly high-dose supplementation (1000–2000mcg) can work just as well as daily low-dose if you understand the passive absorption curve.
Finally, serum B12 testing alone is unreliable for detecting functional deficiency. You need homocysteine and methylmalonic acid levels to confirm status. Most people who "check their B12" are checking a number that can remain normal even while the functional deficiency progresses...