How do B12 and B6 relate to the nervous system?

Several B vitamins relate to the nervous system, but the two with explicit wording are B12 and B6.

What statements are recognised?

Under the annex to Thai Ministry of Public Health Notification No. 447 (B.E. 2566):

Vitamin B12 contributes to the normal function of the brain and nervous system, to the synthesis of an essential substance for red blood cell formation, to normal energy-yielding metabolism, and to the normal function of the immune system.

Vitamin B6 contributes to normal red blood cell formation, to the normal function of the nervous system, to normal energy-yielding metabolism, to normal protein and glycogen metabolism, and to the normal function of the immune system.

What does "normal function" mean?

It means the nutrient takes part in the processes by which the system works normally.

Where does B12 come from?

Only from animal foods and fortified products: meat, fish, shellfish, eggs, milk and dairy.

Plants are not a reliable source of vitamin B12; apart from certain seaweeds, what they contain is largely an inactive analogue, so anyone on a strict vegetarian diet needs to plan for it specifically.

Where does B6 come from?

Fish, meat, liver, potato, banana, dried beans and wholegrains.

How much per day?

Recommended intakes set by the US National Academies' Food and Nutrition Board, as published by the NIH Office of Dietary Supplements, for adults are 2.4 micrograms a day of vitamin B12 and roughly 1.3 to 1.7 mg a day of vitamin B6.

Vitamin B6 has a tolerable upper intake level for adults of 100 mg a day.

Why is B12 always discussed alongside absorption?

Absorbing vitamin B12 depends on a fairly specific process in the stomach and intestine, which is why the amount eaten and the amount the body takes up are not always the same figure.

Dietary supplements are not intended to prevent, treat or cure any disease.