Nutrient Coverage on a Plant-Based Diet

A well-planned plant-based diet can meet adult needs, according to the Academy of Nutrition and Dietetics position paper (Melina et al., 2016), but "well-planned" is the operative phrase. A handful of nutrients are scarce, absent or poorly absorbed from unfortified plant foods, and they deserve a deliberate plan. This page is educational, not medical advice; the reference values below are for healthy adults and are not treatment doses.

The principle: coverage before ranking

Before comparing foods by how impressive they sound, check that a day or week of eating covers the essentials. A ranked list of "superfoods" can look excellent and still leave out B12 or iodine (see How to Rank Foods Honestly: A Transparent Scoring Method for why rankings cannot guarantee this). Two practical rules:

• Do not stack duplicate supplements. A multivitamin, a fortified milk and a separate tablet may all contain the same nutrient.
• Read a supplement label for the serving size, the amount per serving, the chemical form and how often it is taken.

The framework for building meals is in A Plant-Based Eating Framework You Can Repeat; the category checklist is in The Daily Dozen and Roles Over Ingredients.

Reference values at a glance

These are general adult figures from NIH Office of Dietary Supplements and the Dietary Reference Intakes. RDA means a level meeting the needs of nearly all healthy people; AI means an adequate intake where evidence is thinner; UL is an upper limit.

Established These are the published reference values. Provisional How they apply to any one person depends on absorption, health and medication.

Nutrient by nutrient

B12

Vegans have no reliable unfortified source. Fortified foods count only if the label states the amount, you eat a serving, and you do so often enough. Seaweed, spirulina, fermented foods and unfortified nutritional yeast do not reliably supply the active vitamin. Feeling well is not evidence of adequacy, because deficiency can develop slowly. Because regimens differ by absorption and health, ask a clinician or dietitian to choose one, rather than combining several.

Calcium

Low-oxalate greens such as kale, bok choy and broccoli are well absorbed; spinach and chard contain calcium that is poorly absorbed because of oxalate. Calcium-set tofu (look for calcium sulfate and check the label amount) and fortified plant milks are the practical anchors. Add up the labels over a day.

Iodine

Iodized salt supplies about 70 mcg per quarter teaspoon according to NIH, though brands vary. That quarter teaspoon also carries roughly 580 mg of sodium against a daily limit of 2,300 mg in the Dietary Guidelines, so do not raise salt just to hit iodine. Sea salt is often not iodized. Seaweed iodine varies by orders of magnitude and kelp can be excessive. People with thyroid disease need individual advice.

Vitamin D

Sunshine depends on latitude, season, skin, clothing and time outdoors, so it is not a quantified plan. Fortified milks help. Know the difference between the recommended intake and the upper limit, and check existing products before adding more.

Omega-3

ALA from flax, chia, hemp and walnuts is an essential fat. EPA and DHA come directly from fish, and from algae oils. The body converts a small fraction of ALA to EPA and DHA. Whether vegans need direct algal EPA and DHA is debated; no formal requirement exists, and claims about brain or heart benefits are not settled. Check the EPA and DHA amounts on a product, not just "algae oil".

Iron, zinc, selenium and others

Legumes, tofu, whole grains and seeds supply iron and zinc; eating vitamin-C-rich produce (peppers, citrus, tomatoes) alongside legumes improves non-heme iron absorption. Do not take iron without assessment, since excess iron is harmful. Selenium in plants depends on soil; Brazil nuts vary enormously and can be very concentrated, so a daily handful is not a safe precision tool. Choline (AI 550 mg men, 425 mg women) comes from soy, beans, potatoes and broccoli.

Protein and energy

Protein is a coverage item too. See Protein for Muscle on a Plant-Based Diet for targets and portions.

Auditing a representative week

1. Write down a typical week, not an ideal one.
2. Pull out the actual labels of milk, tofu, yogurt and any supplements.
3. Total calcium, B12, iodine and vitamin D from food and supplements against the table.
4. Note gaps and fix the cheapest repeatable one first.

A food log or nutrient database estimates intake. It cannot diagnose status; blood tests and symptoms are for a clinician. The staples that make this easy are in The Practical Kitchen: Staples, Meal Prep and Food Safety.

Safety overrides

General scores yield to individual facts.

• Food allergies come first.
• Fava beans can trigger hemolysis in G6PD deficiency (MedlinePlus).
• Large changes in vitamin K intake matter on warfarin.
• Grapefruit interacts with many medications (FDA).
• Dry kidney beans must be boiled properly; raw cassava is toxic; lupin is a recognised allergen and bitter lupin must be properly prepared.

Reading the sources

The NIH Office of Dietary Supplements publishes a fact sheet per nutrient, with a short consumer version and a longer professional one. Read the professional version for tables and the "health risks from excess" section. Treat them as planning aids, not prescriptions. To weigh claims you meet elsewhere, use Reading Nutrition Evidence: What a Study Can and Cannot Show; for the overview of this wing, see Health and Nutrition: Start Here.

Try this

1. Choose one nutrient from the table and look up its NIH fact sheet. Write down one thing you did not know.
2. Add up calcium across one day's real labels.
3. Check your supplement labels for overlap.

Further reading

• NIH Office of Dietary Supplements fact sheets (ods.od.nih.gov).
• Melina V., Craig W. and Levin S. (2016), Academy of Nutrition and Dietetics position paper on vegetarian diets, J Acad Nutr Diet 116:1970-1980.
• National Academies, Dietary Reference Intakes volumes.
• NHS, "The vegan diet" (nhs.uk).