A well-planned vegan diet can be nutritionally adequate, according to the Academy of Nutrition and Dietetics’ 2025 position for adults. “Planned” means you know which nutrients to watch. Here are the most important ones, with official sources.
In short
- Vitamin B12 is not naturally found in plants: you need fortified foods or a supplement.
- Iron and zinc from plants are absorbed less easily, and people who follow vegetarian or vegan diets are among the groups at risk of zinc deficiency.
- Vitamin D deficiency is more common among people who follow vegan diets; sun exposure matters too.
- The omega-3 in plants is alpha-linolenic acid (ALA), with limited conversion to EPA and DHA.
- For pregnancy, breastfeeding, children or illness, ask a doctor or a dietitian.
The nutrients at a glance
| Nutrient | What the source says | Relevant plant foods |
|---|---|---|
| Vitamin B12 | Not naturally present in plant foods; people who follow vegetarian diets and infants of vegan mothers are among the groups at risk of deficiency. | Fortified foods (many breakfast cereals, nutritional yeast) or supplements. |
| Iron | Plants contain only non-heme iron, which is absorbed less easily; people on vegetarian diets need more iron. Vitamin C and phytate can significantly affect absorption. | Nuts, beans and vegetables; flour is often fortified with iron, so bread, cereal and other grain products are good sources. |
| Calcium | Absorption from some plants may be much lower because of compounds that bind calcium. | Green vegetables (kale, broccoli, Chinese cabbage); juices, milk substitutes, tofu and cereals may be calcium-fortified. |
| Zinc | Beans, nuts and whole grains contain zinc, but with lower bioavailability than animal foods; vegetarians and vegans are among the groups at risk. | Beans, nuts, whole grains. |
| Vitamin D | Deficiency is more common among people on ovo-vegetarian or vegan diets; synthesis from sunlight depends on season, time of day, cloud cover and skin pigment. | Sun exposure, fortified foods and supplements, as appropriate. |
| Omega-3 (ALA) | ALA is converted to EPA and DHA only to a small extent (reported rates under 15%). | Flaxseed, soybean and canola oils; chia seeds, walnuts. |
| Iodine | Seaweed is one of the richest sources, but content varies hugely (16 to 2,984 mcg/g in commercial seaweeds). | Iodised salt; seaweed, with caution because of the wide variation. |
For vitamin B12 and the link between diet and health, see Health and a vegan diet.
How to use the table
- Plan B12 from the start (fortified foods or a supplement) and ask a specialist about the dose.
- Do not rely on a single source for a nutrient: vary legumes, whole grains, vegetables, nuts and seeds.
- Check labels: many plant drinks, cereals and soy products are fortified, but not all.
- For practical ideas, see A balanced vegan diet in practice and What to eat when you go vegan.
The information in this article is for guidance only and does not replace the advice of a doctor or a nutritionist.
Sources
- Academy of Nutrition and Dietetics: Vegetarian Dietary Patterns for Adults (2025)
- NIH Office of Dietary Supplements: Vitamin B12
- NIH Office of Dietary Supplements: Iron
- NIH Office of Dietary Supplements: Calcium
- NIH Office of Dietary Supplements: Zinc
- NIH Office of Dietary Supplements: Vitamin D
- NIH Office of Dietary Supplements: Omega-3 Fatty Acids
- NIH Office of Dietary Supplements: Iodine
Updated: 26 October 2026
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