B vitamin

The B vitamins are a class of of water-soluble vitamins that play important roles in cell metabolism. Though these vitamins share similar names, they are chemically distinct that often coexist in the same foods.

List of B vitamins

 * Vitamin B1 - Thiamine
 * Vitamin B2 - Riboflavin
 * Vitamin B3 - Niacin (nicotinic acid)
 * Vitamin B5 - Pantothenic Acid
 * Vitamin B6 - Pyridoxine (pyridoxal, pyridoxamine)
 * Vitamin B7 - Biotin
 * Vitamin B9 - Folic acid (folate)
 * Vitamin B12 (various forms of Cobalamin; commonly cyanocobalamin or methylcobalamin in vitamin supplements)

Importance to ME/CFS
High Homocysteine may contribute to cognitive issues in ME/CFS and lowering it with B12 and folic acid (or methylfolate) may reduce symptoms