If your B12 levels are low you may be anemic, feel tired or losing more hair then before. You can increase your B12 levels by taking B12 capsules orally in a capsule or sublingual form. If you take a B12 supplement, be sure to take the healthiest forms (i.e. hydrox or methylcobalomin). A different cofactor often used in supplements and/or B12 shots is cyano-cobalamin (i.e. a cyanide cofactor). Cyanide is a heavy metal and therefore it is not ideal to ingest it daily, even in small amounts. This form is often used however since it has a longer shelf life and is less expensive.
Absorption is maximized and thus levels can increase more quickly when B12 is administered intramuscularly (i.e. with a B12 shot). This way, the B12 enters the local circulating, bypassing the entire digestive system. The only forms of B12 used by KIH practitioners are hydrox or methyl-cobalamin.