Plant-Based Basics: Vegan, Vegetarian and the Nutrients to Plan For

By Michael Gonzales · Last updated October 12, 2026 Short answer: "Plant-based" usually means most of what you eat comes from vegetables, fruit, legumes, whole grains, nuts and seeds. Some people go fully vegan; others keep small amounts of fish, eggs or dairy. Either way, a few nutrients deserve attention, and vitamin B12 is the one nearly everyone eating fully plant-based needs from a fortified food or supplement.

Vegan, vegetarian, plant-based: what's the difference?

The Academy of Nutrition and Dietetics says well-planned vegetarian and vegan diets are nutritionally adequate for all stages of life [1]. "Well-planned" is the key phrase.

Nutrients to plan for

Vitamin B12. Found reliably only in animal foods and fortified products such as some plant milks, cereals and nutritional yeast. Adults need about 2.4 mcg a day [2].

Iron. Beans, lentils, tofu, spinach and fortified cereals all contain it, but plant iron is absorbed less well. Eating it with vitamin C (citrus, peppers, tomatoes) helps [3].

Calcium. Calcium-set tofu, fortified plant milks, kale, bok choy and tahini. Spinach is high in calcium on paper but absorbed poorly [4].

Vitamin D. Hard to get from any diet. Fortified plant milks and sunlight help; many people need a supplement, which a doctor can check [5].

Omega-3 fats. Ground flaxseed, chia, hemp seeds and walnuts provide ALA. Algae-based oils provide DHA and EPA directly [6].

Iodine. Iodized salt or seaweed in modest amounts. Sea salt and most specialty salts are not iodized.

Protein. A mix of legumes, soy foods, whole grains, nuts and seeds through the day covers most adults' needs [1].

Building a plate

1. Fill half the plate with vegetables and fruit.
2. Add a palm-sized portion of a protein food: beans, lentils, tofu or tempeh.
3. Add a fist-sized portion of a whole grain or starchy vegetable.
4. Finish with a little fat for flavor and absorption: olive oil, avocado, nuts or seeds.

If you'd rather follow recipes while you get the hang of it, The Complete Plant-Based Cookbook from America's Test Kitchen has plenty to pick from.

Common questions

Will I feel tired eating this way? Tiredness on any new diet often comes from eating too little overall. Plant foods are filling and lower in calories, so portions may need to grow. If fatigue persists, see a doctor; low iron and low B12 are worth ruling out.

Do I have to combine proteins at every meal? No. Eating a variety over the day is enough [1].

Is soy safe? Moderate amounts of whole soy foods such as tofu, tempeh and edamame are part of traditional diets in many countries, and major health organizations consider them a reasonable protein choice.

Where to go next

• What to buy: Electric Food List
• How to plan the week: Meal Plans
• How to shop for less: Grocery Guides
• Breakfast ideas: recipes

This page is general information. People who are pregnant, breastfeeding, managing a health condition or feeding young children should plan a plant-based diet with a doctor or registered dietitian.

Sources

1. Melina V, Craig W, Levin S. Position of the Academy of Nutrition and Dietetics: vegetarian diets. 2016. https://pubmed.ncbi.nlm.nih.gov/27886704/
2. NIH ODS, Vitamin B12. https://ods.od.nih.gov/factsheets/VitaminB12-Consumer/
3. NIH ODS, Iron. https://ods.od.nih.gov/factsheets/Iron-Consumer/
4. NIH ODS, Calcium. https://ods.od.nih.gov/factsheets/Calcium-Consumer/
5. NIH ODS, Vitamin D. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/
6. NIH ODS, Omega-3 fatty acids. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/