The main source of vitamin B12 consists of foods of animal origin (meat, fish, milk and eggs). Its daily requirement is between 2.4 and 2.8 μg,

The vitamin B12 present at the plasma level is linked between 80 and 90% to the haptocorrin protein, this component is metabolically inactive; the remaining 10-20% is bound to the transcobalamin protein, giving rise to the holotranscobalamin complex (HoloTc), and is the biologically active part of vitamin B12.

Other marker of B12 deficiency are the homocysteine ​​levels. In a new study, the levels of holo-TC, B12 and homocysteine ​​were evaluated in 119 vegetarian youngsters. Half was B12 deficient; 70% of males and 50% of females had low plasma olo-TC concentrations; and 92% of males and half of females had hyperhomocysteinemia.

The possibility of vitamin B12 deficiency in vegetarians is high and the timely diagnosis of the deficient states is extremely important, the dosage of holo-TC and homocysteine ​​levels can be a simple and reliable method.

Sadanak Nail et al., Identification of vitamin B12 deficiency in vegetarian Indians. British Journal of Nutrition. 2 2018