Vegan Diets: Nutritious Or Nutrient-Deficient?

Vegan diets are often praised for their health benefits, but they may not contain all the necessary nutrients. A well-planned vegan diet is rich in fruits and vegetables and generally low in highly refined foods. However, any diet that does not contain whole food groups may contribute to a lack of certain nutrients. Animal products can be rich sources of certain nutrients that are more difficult to derive from a plant-based diet.

Vitamin B12 is one of the most well-known nutrients that is lacking in a vegan diet. It is mainly found in animal-sourced foods and plays a vital role in maintaining nerves and normal brain function. Vegans who don't take supplements are at a higher risk of vitamin B12 deficiency, which can cause impaired brain function, neurological disorders, and megaloblastic anemia.

Other nutrients that may be lacking in a vegan diet include omega-3 fatty acids, vitamin D, calcium, iron, zinc, and iodine. Omega-3 fatty acids are important for normal brain development and function, and a deficiency can have adverse effects on mental health. Vitamin D is essential for bone health, and a deficiency can increase the risk of osteoporosis and bone fractures.

Vegan diets may also be lower in protein, which is important for muscle function and energy levels. Additionally, the body's ability to absorb non-heme iron from plant-based sources is lower compared to heme iron from animal sources.

To avoid nutritional deficiencies, it is important for vegans to carefully plan their meals and include a variety of plant-based foods. Fortified foods and supplements can also help ensure adequate nutrient intake.

Vitamin B12

The symptoms of vitamin B12 deficiency include weakness and fatigue, tingling in the hands and feet, problems with the digestive system, a sore tongue or mouth ulcers, feeling faint or dizzy, and a decline in memory, judgment, and understanding. If left untreated, vitamin B12 deficiency can lead to serious health consequences such as pernicious anaemia, certain neurological disorders, and reduced growth and healing.

To ensure adequate vitamin B12 intake, vegans can consume fortified foods or take supplements. Fortified plant-based milk, fortified cereals, and nutritional yeasts are good sources of vitamin B12 for vegans. It is important to check food labels to ensure that the products are fortified with vitamin B12. Additionally, consuming a variety of natural foods such as nutritional yeast, yeast spreads, certain mushrooms, and some algae can also help meet vitamin B12 requirements.

The recommended daily intake of vitamin B12 for adults is 2.4 mcg, while pregnant and breastfeeding women require slightly higher amounts at 2.6 mcg and 2.8 mcg, respectively. To prevent deficiency, vegans should aim to consume at least 3 mcg of vitamin B12 per day through fortified foods or take a daily supplement providing at least 10 mcg.

In summary, vitamin B12 is an essential nutrient that is primarily found in animal-sourced foods. Vegans and vegetarians need to be mindful of their vitamin B12 intake and include fortified foods or supplements in their diet to maintain optimal health.

Vitamin D

The recommended daily amount of vitamin D for people aged one year and above is 600 international units (IU), increasing to 800 IU for those over 70, and 400 IU for babies under one year old.

• Fortified foods such as plant-based milk, orange juice, and breakfast cereals
• Mushrooms, particularly those exposed to ultraviolet light when growing
• Sunshine

It is recommended that vitamin D supplements are taken with a meal to enhance absorption, especially one containing healthy fats such as avocados, nuts, and seeds.

While it may be challenging, it is possible for vegans to get enough vitamin D through a combination of diet, sunshine exposure, and supplements.

Iodine

Symptoms of Iodine Deficiency

• Goiters: swollen lumps on the front of the neck are puffed-up thyroid glands that grow abnormally large when left in a constant, under-functioning state.
• Hypothyroidism: Iodine helps thyroid function, and iodine deficiency means your thyroid will chronically make too few essential metabolic hormones, leading to muscle weakness, weight gain, constipation, cold sensitivity, and other health conditions.
• Weight Gain: Iodine deficiency will slow the metabolism down significantly, meaning your body won't burn calories at an average rate, storing the extra as body fat.
• Hair Loss: Without the proper hormones running through your body, hair follicles will grow slower and shed hair at a faster rate than usual.
• Dry, Flaky Skin: A lack of dietary iodine leads to chronically dry skin that flakes easily.
• Depression: The lack of hormones caused by iodine deficiency can heighten depression as the brain begins to function poorly.

The recommended daily intake of iodine for adults is 140-150 mcg. However, it is also important to avoid too much iodine, as this can lead to thyroid disorders. The US Department of Health states that individuals can consume up to 1,100 mcg of iodine per day, although this is not recommended for optimal health.

Vegan Sources of Iodine

Vegan sources of iodine include wholegrains, green beans, courgettes, kale, spring greens, watercress, strawberries, organic potatoes with skin, and seaweed. Seaweed is an unusually rich source of iodine for vegans. For example, one and a half to two sheets (4 g) of nori can provide the recommended daily intake. However, regular seaweed consumption is not recommended because it provides variable amounts of iodine, and some types of seaweed, such as kelp, contain too much.

Another option for vegans is to take a daily iodine supplement. Some experts recommend that vegans take a daily vitamin and mineral supplement designed for vegans, such as VEG 1, which includes iodine, selenium, and vitamins B12 and D.

Calcium

Some research has shown that vegans have a lower intake of calcium compared to non-vegans, and many studies have shown vegans to have a lower bone mineral density and thus, a higher risk of fractures. Calcium deficiency can have negative implications for bone mass, especially during periods of growth.

The average adult needs roughly 1,000 milligrams of calcium per day. However, during adolescence and childhood, the intake of calcium needs to be higher so that peak bone mass is achieved and conditions such as osteoporosis are prevented later in life.

There are plenty of plant-based sources of calcium available to individuals following a vegan diet, including:

• Fortified soya, rice and oat drinks
• Bread – calcium is added to white and brown flour by law in the UK
• Dried fruit
• Calcium-set tofu
• Soya and linseed bread
• Fortified plant milk
• Fortified yoghurt alternatives
• Kale
• Tahini
• Sweet potatoes
• Watercress
• Okra
• Chia seeds
• Almonds
• Hazelnuts
• Beans, peas and lentils
• Nuts and seeds
• Amaranth and teff
• Seaweed
• Spinach, turnip, mustard, and collard greens
• Figs
• Oranges
• Blackcurrants, blackberries, and raspberries
• Fortified foods and drinks, such as plant yogurts, cereal, flour, cornmeal, plant milks, and orange juice
• Blackstrap molasses

Iron

There are two types of iron: heme iron, which is derived from animal products, and non-heme iron, which comes from plants. Heme iron is more easily absorbed by the body, constituting 40% of the iron in meat, poultry and fish. Non-heme iron, on the other hand, is less well absorbed and makes up the remaining 60% of iron in animal tissue, as well as all the iron in fruits, vegetables, grains and nuts.

Vegan diets only contain non-heme iron, so it is important for vegans to be mindful of their iron intake and to ensure they consume enough iron-rich foods. However, surveys have shown that vegans are no more likely to develop iron-deficiency anaemia than the general population, despite typically having lower iron stores. This may be due to the fact that many vegan-friendly foods are high in iron, such as dried beans, dark green leafy vegetables, tofu, tempeh, and dried fruits. Additionally, vegan diets tend to be rich in vitamin C, which significantly enhances the absorption of non-heme iron.

To maximise iron absorption on a vegan diet, it is recommended to pair iron-rich foods with vitamin C-rich options. For example, one could add bell peppers to a meal of beans and tomato sauce, or include citrus fruits or kiwis in their diet. Tea, coffee, dairy, and foods high in dietary fibre can hinder iron absorption, so these should be consumed separately from iron-rich meals. Using cast-iron cookware can also help increase iron intake, as a small amount of iron may be transferred to the food during cooking.

In summary, while vegans may need to be more mindful of their iron intake, a well-planned vegan diet can provide sufficient iron and even offer better iron sources than animal-derived foods when considering the amount of iron per calorie.

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