Plant Based: The importance of vitamin B12

Nowadays, many athletes have adopted eating habits based on vegan diets. Much has been said about the positive impact of these diets on athletes' performance, mainly due to the increased consumption of antioxidant sources such as polyphenols and micronutrients such as vitamin C and E, which can benefit training and improve recovery.

On the other hand, studies have shown that both athletes and non-exercisers who are following a vegan diet may have lower levels of vitamin B12, calcium, iron and zinc compared to those who consume an omnivorous diet, as these nutrients are more abundant in foods of animal origin, but can be easily corrected through dietary adjustment and also through the use of supplements when necessary. Athletes' diets also need to have a positive protein balance in order to improve recovery processes, muscle anabolism and the body's adaptation.

However, vegan athletes generally consume less protein than those who follow omnivorous diets, taking into account that plant sources of protein have lower amounts of protein per gram of food and have incomplete essential amino acids (aa), as well as being less digestible due to the presence of anti-nutritional factors. It is worth mentioning the limitation of these sources in presenting the amino acids lysine, methionine, isoleucine and tryptophan in the same feed, for example, as they are present in animal sources.

Therefore, it is recommended that the consumption of protein from plant sources be carried out in sufficient quantities, in order to achieve the appropriate values. Another current strategy is to combine these plant sources, known as a ‘protein blend’, in order to acquire meals that have all the essential aa without having to add complete protein sources.

It is known that vitamin B12 intake is higher in individuals who eat a diet based on animal foods (5.6 mcg/d), followed by those who are vegetarians (2.1 mcg/d) and vegans (1.5 mcg/d). Even so, studies show that the levels of this vitamin ingested by the vegan population are below the EAR (Estimated Average Requirements - Dietary Reference Intakes (DRIs)).

Furthermore, this vitamin is important because it participates in functions within the nervous system, homocysteine metabolism and DNA synthesis, and its deficiency in the body is capable of generating morphological changes in blood cells and consequently causing megaloblastic anaemia and neuropathy, which can interfere with sports performance.

Conclusion:

There seems to be a limit to the absorption of oral vitamin B12. Of the 500mcg of the oral supplement ingested, only 10mcg was absorbed. It is therefore recommended that vegan athletes supplement vitamin B12 through fortified foods, plant-based milks, fermented soya, mushrooms, fortified yeast or supplements, but in larger quantities, such as from a dosage of 2.4 mcg/d to 6 mcg/d, for both sexes.

Therefore, monitoring this vitamin and the aaa essential to the body in vegan athletes is extremely important due to the incompleteness of vegetable proteins, as well as their low digestibility and lack of vitamins, especially vitamin B12, which is only found in foods of animal origin. Adequate supplementation or the consumption of foods and vegetable proteins fortified with vitamin B12 is one of the strategies aimed at maintaining the health of vegan individuals and athletes.

Rodney Castro, MSc