Vegan Diets: Nutritionally Sound Or Deficient?

A vegan diet is a plant-based diet that excludes all animal products and their by-products. While veganism has gained popularity, there are concerns about potential nutritional deficiencies. Research shows that vegans may be at risk of lower intakes of specific nutrients, including vitamins B12, B2, B3, D, iodine, zinc, calcium, and protein. This is because these nutrients are either abundant in animal-based foods or have lower bioavailability in plant-based sources.

Vitamin B12, for example, is almost exclusively found in animal-sourced foods, and vegans are at a higher risk of deficiency. Similarly, heme iron, which is more easily absorbed by the body, is only found in meat, especially red meat.

However, it is important to note that a well-planned vegan diet that includes a variety of plant-based protein sources and fortified foods can help prevent these deficiencies. Additionally, supplements can also be taken to ensure adequate nutrient intake.

In conclusion, while there are concerns about nutritional deficiencies in a vegan diet, careful planning, and supplementation can help address these issues.

Vitamin B12

To get sufficient amounts of vitamin B12, people following a vegan diet must take supplements or eat food that has been fortified with this nutrient.

Vitamin D

Public health authorities in the UK recommend that everyone take a vitamin D supplement from October to March to maintain sufficient levels. However, certain groups are advised to consider year-round supplementation, including:

• Under-fives (except for babies consuming 500 ml or more of formula per day)
• People who don't go outside regularly
• People who cover most of their skin when outside
• People with darker skin
• Pregnant and breastfeeding individuals
• People over 65 years old

The recommended daily intake of vitamin D for adults is 10 micrograms, according to the National Institutes of Health.

Iodine

Varying iodine content in plant foods depends on the amount of iodine in the soil they are grown in. Therefore, vegans should consider taking an iodine supplement to avoid deficiency. A daily supplement containing potassium iodide or potassium iodate is recommended, with the amount of iodine not exceeding 150 mcg. Alternatively, vegans can consume iodine-fortified milk alternatives, with an intake of around 500 mL per day.

Calcium

Symptoms of a severe calcium deficiency include:

• Numbness or tingling in the fingers
• Muscle cramps
• Abnormal heart rhythms

Vegan foods that contain calcium include:

• Fortified foods (such as plant-based milk and yoghurt)
• Tofu made with calcium salts
• Soybeans and soy nuts
• Dark, leafy greens (such as bok choy, broccoli, collards, Chinese cabbage, kale, mustard greens, spinach, and okra)
• Sesame seeds and tahini
• 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 amount of calcium in tofu depends on the coagulating agent used to make it. Calcium sulfate and nigari (magnesium chloride) are two commonly used agents. Tofu made with calcium sulfate will contain more calcium than tofu made with nigari.

The calcium recommendation for adults aged 19-50 years and men aged 51-70 years is 1000 mg per day. An intake of 1200 mg of calcium is recommended for women over 51 years and for men over 70.

If you are not eating calcium-rich foods daily as part of a balanced diet, then a calcium supplement may be needed to top up your dietary intake. Speak to a health professional if you have concerns about your calcium intake.

Zinc

However, vegans may be at risk of zinc deficiency due to the presence of phytates in plant foods, which reduce zinc absorption. Studies have shown that vegetarians and vegans have lower zinc intakes and blood zinc levels than non-vegetarians. As a result, vegans may need to consume 50% more zinc than meat-eaters, with recommendations of 12 mg per day for vegan women and 16.5 mg per day for vegan men.

Symptoms of zinc deficiency include hair loss, more infections, poor wound healing, fatigue, loss of appetite, diarrhoea, skin sores, delayed puberty, and impaired testicular function in men. If a vegan is experiencing any of these symptoms, a modest zinc supplement of about 50-100% of the RDA may be beneficial.

To improve zinc absorption, vegans can use food processing techniques such as soaking, heating, sprouting, fermenting, and leavening. Including zinc-dense foods in meals throughout the day can also help meet the recommended intake.

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