Vegan Diets: Supplementing For Optimal Health

A vegan diet can be a healthy choice, offering benefits such as lower blood pressure and cholesterol, and a reduced risk of heart disease, stroke, and diabetes. However, vegans need to be mindful of potential nutritional gaps and supplement their diet to avoid deficiencies. This is because some vitamins and minerals are harder to obtain from plants alone. For example, vitamin B12 is primarily found in animal products, so vegans may need to include fortified foods or take a supplement to meet their daily requirements. Similarly, vitamins D and K, calcium, zinc, iodine, and omega-3 fatty acids are important nutrients that vegans may need to supplement. A well-planned vegan diet, with careful consideration of nutrient-dense plant-based foods and appropriate supplementation, can ensure that vegans obtain all the necessary nutrients for optimal health.

Vitamin B12

The daily recommended intake of vitamin B12 is 2.4 mcg for most adults. If you're pregnant or nursing, you may need to take more. B12 is available over the counter as a tablet or sublingual lozenge. It's also available as a prescription shot or nasal spray.

It's important to keep in mind that vitamin B12 is best absorbed in small doses. The less frequently you ingest vitamin B12, the more you need to take. So, vegans who are unable to reach the recommended daily intake using fortified foods should opt for a daily supplement providing 25–100 mcg of cyanocobalamin or a weekly dosage of 2,000 mcg.

Some foods that vegans can eat to get vitamin B12 include fortified breakfast cereals, fortified meat substitutes, fortified plant-based milk, and fortified nutritional yeast. However, according to the Academy of Nutrition and Dietetics, fermented foods, seaweed, spirulina, chlorella algae, and unfortified nutritional yeast are not reliable sources of B12.

Vitamin D

Sources of Vitamin D for Vegans

• Fortified foods: Fortified plant-based milk (soy, almond, oat), fortified breakfast cereals, fortified orange juice, and fortified spreads.
• Sunlight: Spending 15 minutes in the midday sun without sunscreen and exposing most of the skin is usually enough to produce adequate vitamin D.
• Supplements: If you are unable to get enough vitamin D from fortified foods and sunlight, consider taking a daily vitamin D2 or vegan vitamin D3 supplement. Vitamin D3 is derived from fish or sheep lanolin, so be sure to choose a vegan product.

Calcium

Fortified Foods:

• Opt for calcium-fortified plant-based milk and yoghurt alternatives. Most plant-based milk alternatives like soy milk, oat milk, and almond milk are fortified with calcium.
• Include calcium-fortified orange juice in your diet.
• Choose calcium-set tofu, which is prepared with calcium sulfate, over regular tofu. Check the ingredients list to identify if calcium has been used as a firming agent.
• Include calcium-fortified cereals in your breakfast, such as ready oat cereal or soya and linseed bread.

Whole Foods:

• Dark leafy greens like kale, watercress, bok choy, broccoli, collards, mustard greens, and Chinese cabbage are excellent sources of calcium.
• Legumes, especially white beans (navy beans) and kidney beans, are rich in calcium.
• Nuts and seeds, particularly almonds, tahini (sesame seed butter), and hazelnuts, provide a good amount of calcium.
• Dried fruits like dried figs are also a good source.
• Other options include sweet potatoes, okra, chia seeds, and edamame.

Tips for Optimising Calcium Absorption:

• Vitamin D is essential for calcium absorption. Ensure you get enough exposure to sunlight, or consider taking vitamin D supplements, especially during seasons with less sunlight.
• Blanching, soaking, or sprouting certain vegetables can reduce the presence of oxalates and phytates, which inhibit calcium absorption.
• Speak to a healthcare professional if you have concerns about your calcium intake or if you exhibit signs of calcium deficiency, such as muscle cramping, brittle nails, poor circulation, or irregular heartbeat. They may recommend a calcium supplement to ensure you meet your daily requirements.

Iodine

Other vegan sources of iodine include wholegrains, green beans, courgettes, kale, spring greens, watercress, strawberries, organic potatoes with skin, and iodised salt. However, amounts tend to be low and variable depending on how much iodine is in the soil.

The iodine content of a particular plant food varies depending on how much iodine was present in its growing environment. There is no easy way of knowing how much iodine is in plant foods, but they may contain low amounts. It is therefore recommended that vegans supplement their iodine intake to avoid iodine deficiency.

The recommended daily intake of iodine for adults in the UK is 140 mcg, while in the US it is 150 mcg.

Excessive iodine consumption will stop thyroid hormone production and can lead to hypothyroidism, autoimmunity, and hyperthyroidism.

Iron

There are two types of dietary iron: heme and non-heme. Heme iron is found in animal products and is easily absorbed by the body. Non-heme iron is found in vegan foods and is not as easily absorbed. However, vegans are no more likely to develop iron deficiency anaemia than the general population. This is because a vegan diet is typically high in vitamin C, which improves the absorption of non-heme iron.

• Eat iron-rich foods: dried beans, dark green leafy vegetables, dried fruits, nuts and seeds, wholegrain cereals and breads, and iron-fortified products.
• Boost iron absorption by pairing iron-rich foods with vitamin C-rich foods. For example, add bell peppers to a houmous and mixed bean wrap, or pineapple to a lentil curry.
• Avoid drinking tea or coffee with meals and for at least an hour before or after, as they can reduce iron absorption.
• Cook with cast-iron pans, as a small amount of iron may be transferred to food during cooking.
• Be aware that spinach contains oxalates, which block iron absorption.

Frequently asked questions