Vegan Diets: Nutritionally Complete Or Incomplete?

A vegan diet is based on plants and foods made from plants, including vegetables, grains, nuts, and fruits. Vegans do not eat foods that come from animals, including meat, eggs, and dairy.

A well-planned vegan diet can be nutritionally complete and provide various health benefits. Vegans tend to eat more fruits and vegetables, which means their diets are loaded with fiber, plant protein, and minerals.

However, vegans may be at risk of certain nutrient deficiencies, including vitamin B12, vitamin D, long-chain omega-3s, iodine, iron, calcium, and zinc.

- Vitamin B12: Essential for cell activities, DNA synthesis, and neurological function. Found in animal products, fortified foods, and supplements.

- Protein: Essential for muscle and bone structure and various bodily functions. Include legumes, whole grains, nuts, and seeds in your diet.

- Omega-3 Fatty Acids: Linked to lower rates of heart disease and some cancers. Found in algae-based supplements, chia, flax, and walnuts.

- Vitamin A: Essential for vision, immune function, and reproduction. Found in orange and green vegetables and fruits.

- Calcium: Needed for bone health. Include calcium-fortified plant milk and juice, calcium-set tofu, leafy greens, and dried fruit in your diet.

- Iodine: Crucial for thyroid health. Include iodized salt or a supplement in your diet.

- Iron: Needed for red blood cell production. Include iron-rich plant foods and vitamin C-rich foods to enhance absorption.

- Zinc: Found in protein-rich foods and needed for various bodily functions. Include plant-based sources like beans, nuts, and whole grains in your diet.

Getting the right nutrients from a vegan diet

A vegan diet is based on plants and foods made from plants, including vegetables, grains, nuts and fruits. Vegans do not eat foods that come from animals, including meat, eggs and dairy.

• Protein – Protein gives our muscles and bones structure and is used for fighting infection, speeding up reactions, making hormones, carrying oxygen and repair. Good vegan sources of protein include tofu, tempeh, beans, pulses, nuts, seeds, whole grains and legumes.
• Omega-3 fats – Omega-3 fats affect many aspects of our health, including our immune system, brain, nerves and eyes. Good sources of omega-3 fats for vegans include chia, hemp, flaxseeds, walnuts, and soybeans.
• Calcium – Calcium is involved in bone health, your nervous system, blood clotting and controlling your muscles. Good sources of calcium for vegans include green, leafy vegetables such as broccoli, cabbage and okra, and dried fruit such as raisins, prunes, figs and dried apricots.
• Vitamin D – Vitamin D helps to keep our bones and muscles healthy. Good sources of vitamin D for vegans include sunlight, fortified foods such as breakfast cereals and non-dairy milk alternatives, and supplements.
• Iodine – Iodine is used by your body to make thyroid hormones, which control how fast your cells work. Good sources of iodine for vegans include supplements containing potassium iodide/iodate and iodine-fortified plant milk.
• Selenium – Selenium is part of many important enzymes, which speed up reactions in our bodies. Using a supplement containing selenium is a reliable way of guaranteeing an adequate intake.
• Iron – Iron is used to help speed up reactions in your body. If your body is running low on iron, you may become tired and anaemic. Good sources of iron for vegans include legumes, whole grains, nuts, seeds, dried fruit, green leafy vegetables and fortified breakfast cereals.
• Zinc – Our bodies use zinc for a variety of functions, including speeding up reactions and fighting infection. Good sources of zinc for vegans include wholegrain bread, peas, corn, nuts, carrots, whole grains, wheat germ, soybeans, cabbage, radish, watercress, legumes and fortified breakfast cereals.
• Vitamin K – Vitamin K plays a role in blood clotting, bone health and the functioning of our kidneys. Good sources of vitamin K for vegans include leafy green vegetables.
• Vitamin A – Our bodies turn carotenoids from plant foods into vitamin A, which is required for eye health and the normal functioning of our immune systems. Good sources of carotenoids for vegans include orange and yellow fruits and vegetables such as cantaloupe, carrots, sweet potatoes, kale, spinach and swiss chard.

• Eat a varied and balanced diet containing adequate calories.
• Eat a variety of foods as amino acid limitation is not as serious.
• Eat at least five portions of fruit and vegetables every day.
• Base meals on potatoes, bread, rice, pasta or other starchy carbohydrates.
• Eat fortified foods or take supplements containing nutrients that are more difficult to get through a vegan diet, including vitamin D, vitamin B12, iodine, selenium, calcium and iron.
• Drink plenty of fluids.
• Limit foods and drinks that are high in fat, salt or sugar.

Vegan sources of calcium and vitamin D

Calcium is needed to maintain healthy bones and teeth. While non-vegans get most of their calcium from dairy foods, vegans can get it from other foods. Good sources of calcium for vegans include:

• Green, leafy vegetables such as broccoli, cabbage, and okra, but not spinach (spinach does contain high levels of calcium, but the body cannot digest it all)
• Fortified unsweetened soya, pea, and oat drinks
• Sesame seeds and tahini
• Brown and white bread (in the UK, calcium is added to white and brown flour by law)
• Dried fruit, such as raisins, prunes, figs, and dried apricots

The body needs vitamin D to regulate the amount of calcium and phosphate, which help keep bones, teeth, and muscles healthy. Good sources of vitamin D for vegans include:

• Exposure to sunlight, particularly from late March/early April to the end of September
• Fortified fat spreads, breakfast cereals, and unsweetened soya drinks (with vitamin D added)
• Vitamin D supplements – everyone should consider taking a daily supplement during autumn and winter, as it's difficult to get enough from food alone

Vitamin D supplements should be chosen carefully by vegans, as some contain animal products.

Vegan sources of iron

A vegan diet can be high in iron, although the body absorbs iron from plant-based foods less effectively than iron from meat.

• Wholemeal bread and flour
• Breakfast cereals fortified with iron
• Dark green, leafy vegetables, such as watercress, broccoli, and spring greens
• Dried fruits, such as apricots, prunes, and figs

Vegan sources of vitamin B12

Vitamin B12 is essential for human health, and a deficiency can have severe consequences. As vitamin B12 is mainly found in meat, eggs, and dairy products, vegans must take particular care to consume enough of it.

Vegans can get their vitamin B12 from fortified foods such as:

• Fortified plant-based milk
• Fortified cereals
• Nutritional yeast
• Fortified breakfast cereals
• Fortified non-dairy milk
• Fortified vegan meats
• Yeast spreads, such as Marmite and Vegemite

Vitamin B12 can also be sourced from supplements, which are recommended for vegans even if they have a reliable intake of B12-fortified foods.

Vegan sources of omega-3 fatty acids

A vegan diet can be a nutritionally complete way of eating, but careful planning is required to ensure you get all the nutrients your body needs.

One nutrient vegans may be deficient in is omega-3 fatty acids, which are important for maintaining heart and brain health and reducing inflammation. Omega-3 fatty acids are found in three different forms: DHA, EPA, and ALA. While DHA and EPA are more commonly found in animal products, ALA is abundant in plant-based sources.

ALA can be converted into EPA and then into DHA, but conversion rates are less than 15%. Therefore, vegans may need to increase their intake of omega-3 fats to help give their body the nutrition it needs.

• Walnuts are loaded with healthy fats and ALA omega-3 fatty acids. Studies have found that walnuts could help improve brain health as a result of their omega-3 content. Just one ounce of walnuts can fulfill an entire day’s requirements of omega-3 fatty acids.
• Chia seeds are known for their many health benefits, providing a hefty dose of fiber and protein in each serving. They’re also a great plant-based source of ALA omega-3 fatty acids. One ounce of chia seeds provides 5,000 mg of ALA omega-3 fatty acids, far exceeding the daily recommended intake.
• Hemp seeds contain about 30% oil and are a good source of omega-3s. Studies have found that the omega-3s found in hemp seeds could benefit heart health by preventing the formation of blood clots and helping the heart recover after a heart attack. Three tablespoons of hemp seeds contain approximately 2,600 mg of ALA.
• Flaxseed is a nutritional powerhouse, providing a good amount of fiber, protein, magnesium, and manganese in each serving. It’s also an excellent source of omega-3s. Flaxseed and flaxseed oil have been shown to reduce cholesterol in multiple studies. One tablespoon of whole flaxseed contains 2,350 mg of ALA omega-3 fatty acids, surpassing the daily recommended amount.
• Perilla oil is a good source of omega-3 fatty acids, with ALA making up an estimated 64% of this seed oil. Each tablespoon contains nearly 9,000 mg of ALA omega-3 fatty acids. To maximize its health benefits, perilla oil should be used as a flavor enhancer or dressing, rather than a cooking oil.
• Algal oil is one of the few vegan sources of both EPA and DHA. Studies have found that it’s comparable to seafood in regard to its nutritional availability of EPA and DHA. Algal oil supplements typically provide 400–500 mg of combined DHA and EPA.

Frequently asked questions