TABLE 3.
Energy/nutrient inadequacies and dietary advice for different populations following vegan, vegetarian, pescatarian, or flexitarian diets/TDDs1
| Nutrient | Function | Food sources | Advice |
|---|---|---|---|
| Good-quality proteins | Involved in a wide range of metabolic interactions; essential for growth and repair; help maintain healthy skin, bones, muscles, and organs (206, 207) | Eggs; milk and dairy products; soy products; meat substitutes; legumes; lentils; nuts; seeds; selected whole grains (207) | People following vegan/vegetarian/flexitarian/TDD diets should aim to replace meat protein sources with high-quality protein alternatives; to ensure nutritional adequacy, HCP advice may particularly be required for young children and pregnant women |
| Calcium | Helps develop and maintain healthy teeth and bones; vital roles in intracellular signaling for metabolic regulation, information transmission via the nervous system, muscle contraction, and blood clotting (206, 208) | Milk and dairy products; low-oxalate green-leafy vegetables with high calcium bioavailability, such as kale (106, 107); calcium-enriched plant-based milks and products (e.g., soya milk, yogurt, oat milk and yogurt, coconut milk and yoghurt, and tofu); calcium-enriched juices; fortified cereals; sesame paste (tahini); almonds; seaweed and figs (206) | If insufficient calcium-enriched plant-based alternatives are consumed, HCP advice needs to be sought to advise a suitable calcium supplement |
| n–3 Fatty acids | Essential fatty acid that must be supplied by diet; important components of cell membranes; substrates for signaling molecules that control cellular functions; important for heart health (206, 209) | Oily fish; n–3 enriched eggs; canola/rapeseed oil; walnuts; ground flaxseed; hemp seed; chia seed; fortified products (206) | If no fish is consumed (i.e., vegan, vegetarian diet) HCP advice may be required to advise on vegetarian sources of DHA and EPA and suitable supplementation may be needed |
| Iron | Component of hemoglobin in RBCs, allowing oxygen transportation; important roles in the immune system; required for energy and drug metabolism (206, 208) | Heme sources: beef, liver; nonheme sources: dried beans and peas; lentils; enriched cereals; nuts and seeds, selected whole-grain products; dark leafy green vegetables but bioavailability can be low due to phytate and tannin content; dried fruit; eating foods rich in vitamin C helps absorb nonheme iron (206) | In high-risk population (i.e., young children and during pregnancy), an iron supplement may be needed if intake of nonheme/heme alternatives do not meet iron requirements |
| Zinc | Co-factor for many enzymes involved in digestion, carbohydrate and bone metabolism, oxygen transport, immune response, stabilizing the structure of DNA, RNA, and ribosomes (210) | Beef; crab and shellfish; lamb; leafy or root vegetables; whole grains; pork; poultry; milk and dairy products; eggs; nuts; offal (210); foods high in phytates (e.g., whole grains) reduce the bioavailability of zinc | In high-risk populations (i.e., young children) and, in particular, if growth is affected, a zinc supplement may be required |
| Iodine | Maintenance of metabolic rate controlling energy production and oxygen consumption; growth and cognitive development; protein metabolism in fetuses/neonates (210) | Milk and dairy products; sea fish; seaweed; iodized salt, local iodine fortified foods (210) | In particular, young vegan children may need an iodine supplement, as salt intake should be limited in the young |
| Selenium | Protects against oxidative damage; antioxidant and transport functions (210) | Offal; fish; Brazil nuts; eggs; poultry; meat products (210) | HCP advice may be required to assess need for selenium supplementation, in particular in individuals who are vegetarian/vegan |
| Vitamin A (retinol, beta-carotene) | Involved in adaptation of vision in the dark, growth, cell differentiation, embryogenesis, immune response (210) | Retinol: liver products, kidney, offal, oily fish and fish liver oils, eggs; beta-carotene: carrots, red peppers, spinach, broccoli, tomatoes (210) | There are many sources of plant-based alternatives for vitamin A; however, availability of these alternatives needs to be considered in conjunction with local prevalence of vitamin A deficiency; HCP advice may be useful on whether supplementation is required |
| Riboflavin (vitamin B-2) | Oxidation-reduction reactions in metabolic pathways; promotion of normal growth; assists synthesis of steroids, RBCs, and glycogen; maintenance of mucous membrane, skin, eyes and nervous system; aids iron absorption (210) | Eggs; milk and dairy products; liver; kidney; yeast extract; fortified breakfast cereal (210) | Ensure that nutritional alternatives are consumed, in particular in individuals who follow vegan diets |
| Niacin (vitamin B-3) | Glycolysis; fatty acid metabolism; detoxification | Beef; pork; chicken; wheat flour; maize flour; eggs; milk and dairy products (210) | Ensure that nutritional alternatives are consumed, in particular in individuals who follow vegan diets |
| Vitamin B-12 (cobalamin) | Recycles folate coenzymes; normal myelination of nerves; synthesis of methionine from homocysteine (210) | Meat products; eggs; milk and dairy products; fish products; yeast products; fortified vegetable extracts; fortified breakfast cereal (210) | HCP advice may be required, in particular if a vegan diet is followed; a vitamin B-12 supplement may be required |
| Vitamin D (calciferols) | Calcium absorption and excretion; involved in bone mineralization; may inhibit cell proliferation in some forms of cancer (210) | Cod liver oil; oily fish; fortified milk and dairy products; fortified margarine; fortified breakfast cereals; eggs (in particular, egg yolk); liver | The WHO supports routine supplementation for a wide range of populations (204); local advice for vitamin D supplementation should be followed and the increased risk of vitamin D deficiency with a plant-based diet should be considered |
1
HCP, health care professional; TDD, territorial diversified diet.