When following a vegetarian or vegan diet, it can be hard to know if you’re still meeting all your nutritional needs, particularly for nutrients found mostly in animal products. This article discusses four key vitamins and minerals that are harder to get on a veg~n diet, and how you can meet your needs through diet or supplements. It also highlights five other nutrients you may want to be aware of.

In general, following a varied, balanced healthy diet means it should be possible to meet all your nutritional needs without the need for any supplements. However, some nutrients are mainly available in meat, fish, poultry, dairy or eggs. For people who don’t eat these products regularly, it can be useful to look at how you get the nutrition you need. In some cases, it may help to choose food and drink fortified with added nutrients, consider taking a dietary supplement, or simply to vary your diet.

Our nutritional needs vary by life stage. For instance, pregnant or breastfeeding women, or children, will have different requirements to healthy adults. This article provides information for healthy men and women aged over 18 and contains information specific to the New Zealand context.

Key nutrients for vegetarians and vegans

Vitamin B12

Vitamin B12 is essential for making red blood cells and maintaining a healthy nervous system. It also supports DNA synthesis and helps to release energy from food. Vitamin B12 can be obtained from dairy products and eggs, or from products fortified with vitamin B12, including plant-based milk, nutritional yeast, yeast extract, and breakfast cereals.

People who don’t eat any animal products will need take a vitamin B12 supplement, or have foods or drinks fortified with vitamin B12 at least twice a day (National Health and Medical Research Council et al., 2006; The Vegan Society, 2020). If taking a supplement, aim for at least 10 micrograms (µg) daily, or at least 2,000 micrograms (µg) weekly (The Vegan Society, 2020).

Vitamin D

Vitamin D helps the body to absorb calcium and phosphorus, and to maintain appropriate levels of calcium and phosphorus in the body. In turn, this helps keep bones, teeth and muscles healthy. Vitamin D also helps to improve immunity. Vitamin D can be found naturally in egg yolks and dairy products. It is also in products fortified with vitamin D, including dairy foods, margarine, breakfast cereals, and plant-based milks.

Because very few foods contain significant amounts of vitamin D, it is hard to obtain enough from the diet alone. However, the body also makes vitamin D from direct sunlight exposure on the skin. To produce the vitamin D you need, aim for 8 minutes outdoors in the sun during summer, or 30 minutes during winter, and be sure to practice good sun protection (Healthify He Puna Waiora, 2020a; New Zealand Nutrition Foundation, 2022c).

In New Zealand, most people get enough vitamin D from sun exposure and diet. Supplementation is generally recommended only for those who have very limited sun exposure or have dark-coloured skin. (Healthify He Puna Waiora, 2020a, 2020b; National Health and Medical Research Council et al., 2006). If taking a vitamin D supplement, aim for no more than 10 micrograms (µg) per day. You may sometimes see this written as 400 International Units (IU) of vitamin D.

Iodine

Iodine helps make thyroid hormone, which is responsible for ensuring a healthy metabolic rate and normal growth and development. Iodine is found in dairy products, eggs, seaweed, iodised salt, most commercial bread, and plant-based milks fortified with iodine.

If you follow a varied and balanced veg~n diet that includes foods and drinks containing iodine, supplements are usually not needed (Healthify He Puna Waiora, 2022; National Health and Medical Research Council et al., 2006). If you choose to take iodine supplements, it's best to do this under guidance from a doctor or dietitian, as iodine and kelp supplements sometimes contain very high levels of iodine that exceed the safe upper limit (Healthify He Puna Waiora, 2022).

Selenium

Selenium works as an antioxidant that protects the body from damage caused by free radicals. It is important for reproduction, and supports a well-functioning immune system, healthy hair and nails. Selenium can be found in eggs, Brazil nuts, mushrooms, brown rice, tofu, and lentils. Just one Brazil nut meets the daily selenium requirements.

If following a varied, well-planned diet that includes daily sources of foods containing selenium, a supplement shouldn’t be needed. If you want to take selenium supplements, it’s best to talk to a doctor or dietitian first, as excess selenium can cause adverse outcomes (New Zealand Nutrition Foundation, 2022b; NHS, 2020).

Other important nutrients for vegetarians and vegans

Supplementation of the following nutrients is generally not required, as dietary intakes for both vegetarians and vegans are usually adequate. However, people following a veg~n diet may want to be aware of these nutrients.

Protein

Protein supports body growth and repair, and also provides a source of energy. Vegans and vegetarians following a balanced diet can easily meet their protein needs (New Zealand Nutrition Foundation, 2022a). Protein derived from plant-based foods is sometimes referred to as ‘incomplete’ because that food lacks one or more essential amino acids. However, it is possible to obtain the full range of amino acids just by eating a variety of plant foods. Good sources of protein include dairy products, eggs, cereals, legumes (beans, peas and lentils), edamame, tofu, plant-based milks, nuts, and seeds.

Calcium

Calcium is essential to maintain healthy bones and teeth. Dairy products are a major dietary source of calcium. People who do not eat dairy are able to meet their needs by consuming plant-based milks fortified with calcium, tofu, green leafy vegetables, nuts, and seeds (National Health and Medical Research Council et al., 2006). It is also important to have adequate vitamin D in your diet, as vitamin D improves your body’s absorption of calcium – see Vitamin D.

Iron

Iron helps to carry oxygen around the body and supports a healthy immune system. There are two types of iron: haem iron (from meat, fish, and poultry) and non-haem iron (from plant foods). Non-haem iron is absorbed by the body less well than haem iron. However, you can improve your body’s ability to absorb iron by consuming vitamin C (eg, tomato, capsicum, citrus fruits, kiwifruit) with your meal. Most people should be able to meet their iron needs through a healthy, balanced diet. Tofu, legumes, dark green leafy vegetables, eggs, wholegrain bread, and breakfast cereals fortified with iron are all good iron sources.

Zinc

Zinc is important for immune support and wound healing. It also supports a healthy metabolism. Zinc derived from plant foods is not absorbed by the body as well as zinc from animal sources. However, consuming zinc with high-protein foods can increase zinc absorption. People who do not eat meat should be able to meet their zinc requirements by eating dairy foods, wholegrains, legumes, breakfast cereals fortified with zinc, and nuts and seeds (National Health and Medical Research Council et al., 2006).

Omega-3

Omega-3 helps to maintain a healthy heart and supports healthy brain function. It is an essential fat that our bodies cannot make and must come from the food we eat. Food sources include walnuts, chia seeds, canola oil, flaxseeds, hempseeds, and their oil. Vegetarians and vegans who consume these products daily should be able to meet their omega-3 requirements.

Conclusion and Recommendations

• Ultimately, the decision to take nutritional supplements depends on individual need and preference. For vegetarians and vegans, supplementation may not be necessary if you follow a varied, balanced diet that includes plenty of fortified foods.
• If you’re concerned that you’re not meeting your nutritional needs, your doctor can arrange a test for you. A dietitian can also help you develop a plan for how to safely address any deficiencies.
• Don’t be tempted to take a higher dose of supplements than recommended, as excessive supplement use can be harmful to the body, particularly over the long term.
• To see if a product is fortified, read the label. Any product that has been fortified with a vitamin or mineral should also state how much of that nutrient it contains.
• Click here for great resources on nutrition for vegetarians and vegans.

By Catherine Lofthouse

Catherine Lofthouse is a passionate plant-based foodie who loves to explore all things related to veg~n living. She is also a registered dietitian.

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References

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3. Healthify He Puna Waiora. (2022, November 10). Iodine. Healthify. https://healthify.nz/hauora-we...
4. National Health and Medical Research Council, Australian Government Department of Health and Ageing, & New Zealand Ministry of Health. (2006). Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes. National Health and Medical Research Council.
5. New Zealand Nutrition Foundation. (2022a). Protein. NZ Nutrition Foundation. https://nutritionfoundation.or...
6. New Zealand Nutrition Foundation. (2022b). Selenium. NZ Nutrition Foundation. https://nutritionfoundation.or...
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8. NHS. (2020). Vitamins and minerals—Others. Nhs.Uk. https://www.nhs.uk/conditions/...
9. The Vegan Society. (2020). The Vegan Eatwell Guide. https://www.vegansociety.com/s...