Vitamin B12 is essential for a healthy nervous system, it promotes healthy growth in children and is necessary for the production of red blood cells. Since plants do not make vitamin B12, there is a high risk of developing a vitamin B12 deficiency if you eat a vegan or whole food plant-based diet.
Why you need Vitamin B12
Vitamin B12 is a water-soluble vitamin that contains the mineral, cobalt at its centre. Just like other B-vitamins, it helps to convert the food you eat into energy for your cells and tissues.
Vitamin B12 assists in the production of the myelin sheaths that protect your nerves and regulates the transmission of electrical signals down them.
It helps your body to get rid of the harmful amino acid, homocysteine, a by-product of protein synthesis. If homocysteine builds up in your body, it can damage the lining of your blood vessels and trigger heart disease.
Vitamin B12 regulates DNA synthesis and is thus crucial for cell division especially during times of rapid growth.
Symptoms of deficiency
You can become deficient in vitamin B12 if you don’t get enough of it through your diet or if you don’t absorb it properly. Some of the symptoms of vitamin B12 deficiency include:
- Pernicious anaemia: Your red blood cells need vitamin B12 to divide appropriately into healthy, normal-sized cells. Without vitamin B12, your red blood cells divide abnormally and form large, immature cells that do not function as blood cells. These cells have a much lower capacity to carry oxygen and results in constant feelings of fatigue, weakness, shortness of breath and skin paleness.
- Increased blood levels of homocysteine: Your levels of homocysteine increase with a vitamin B12 deficiency. Your arteries may begin to clog due to plaque accumulation resulting in heart disease and possibly strokes.
- Neurological damage: A vitamin B12 deficiency affects the nerve cells, spinal cord and the brain. Symptoms such as numbness, depression, irritability, insomnia, poor concentration, lack of sensation and even paralysis can occur.
Sources of Vitamin B12 for Vegans
Plants or animals do not make vitamin B12, it is, in fact, produced by bacteria. Humans used to get their B12 by eating foods contaminated with bacteria that had created the B12. Since we clean our food thoroughly before we eat it these days, we cannot get a reliable source of B12-containing bacteria.
Government guidelines recommend a daily intake of 2.4mcg (micrograms) of vitamin B12. However, some studies suggest that you may need doses of up to 7mcg per day to prevent homocysteine build up and stabilise your vitamin B12 levels.
It is a good idea to spread your vitamin B12 intake throughout the day to maximise the amount you absorb.
Some food sources of vitamin B12 include:
- Fortified cereals
- Fortified soy, oat, almond and cashew milk
- Nutritional yeast flakes such as Red Star Vegetarian Support Formula
- Fortified soy and coconut yoghurt
- Fermented foods like tempeh and miso
- Fortified mock cheese and meats.
Supplements are probably the most reliable way to get vitamin B12. You can either take a supplement that provides at least 25 mcg of B12 daily or one that provides1000mcg at least twice a week. Vitamin B12 is not toxic even at high doses because your body excretes whatever it doesn’t need via urine. So, there’s no need to panic if you exceed these doses.
You can get vitamin B12 supplements in either the cyanocobalamin form or in the methylcobalamin form. Cyanocobalamin is the most cost-effective to produce, and it is quite stable. Your body needs to convert it to methylcobalamin before it can absorb it.
However, it releases a tiny amount of cyanide during this conversion process. According to scientists, this amount of cyanide is insignificant and doesn’t affect you negatively.
If you have kidney problems or if you smoke, the conversion from cyanocobalamin to methylcobalamin may be inefficient, so it is a better idea to take methylcobalamin directly.