Vitamin B12: Straight Facts on cyanocobalamin and methylcobalamin
Question 1: Is the Cyanocobalamin form of Vitamin B12 safe?
Answer 1: YES! Cyanocobalamin is very safe! A number of foods contain cyanide including almonds, Lima beans and any fruit with a pit such as apples and peaches. Eating one almond can deliver over 15 times the amount of cyanide in a daily dose of cyanocobalamin from Shaklee B Complex. Cyanide toxicity is treated by injecting hydroxocobalamin so that body can turn cyanide into cyanocobalamin by making cyanide bind with cobalamin to be excreted via urine safely.
Question 2: Methylcobalamin is natural?
Answer 2: NO! Methylcobalamin is synthetic. The starting material for its synthesis can be either cyanocobalamin or hydroxocobalamin.
Question 3: People with methylation defect must take the methylcobalamin form of Vitamin B12?
Answer 3: NO! Both the methyl-group and the cyanide-group have to be removed in the cell to become a free form of cobalamin. Then, the free cobalamin is incorporated into the cofactor forms (methylcobalamin and adenosyl-cobalamin) that the cell utilizes. People with methylation defect can utilize cyanocobalamin and supplementing with methylcobalamin is unlikely to be more advantageous than supplementing with cyanocobalamin for people with methylation defect or the general population.
Please find detailed explanations / answers in the pdf:
Cyanocobalamin vs. Methylcobalamin Overview (PDF)