Interactions of cobalamin (vitamin B12) with other micronutrients (vital substances):
Vitamin B12, vitamin B6, and folic acid
The metabolism of homocysteine, which plays a mediating role in the metabolism of sulfur-containing amino acids, provides an example of the interdependence of vital substances to optimize or maintain physiological functions and thus health.Healthy individuals can metabolize homocysteine in two ways:
- Synthesis of methionine from homocysteine using a folate coenzyme and a vitamin B12-dependent enzyme.
- Conversion of homocysteine into another amino acid – cysteine – with the help of a vitamin B6-dependent enzyme.
Consequently, the amount of homocysteine in the blood is regulated by three vitamins: Folic acid, vitamin B12 and vitamin B6.
An intake of 5 mg of synthetic folic acid and more can mask a vitamin B12 deficiency, that is, the hematological symptoms identical in vitamin B12 and folic acid deficiency, such as megaloblastic anemia (anemia caused by a deficiency of vitamin B12 or, less often, by a deficiency of folic acid) are improved due to folic acid intake, while the neurological symptoms of vitamin B12 deficiency can not be prevented. Therefore, the diagnosis of nervous system dysfunction due to vitamin B12- deficiency may be complicated if folic acid intake is excessive at the same time.
