Vitamin B12 is an essential water-soluble vitamin that is commonly found in a variety of animal foods such as fish, shellfish, meat and dairy products. Synthetic vitamin B12 is frequently used in combination with other B vitamins in vitamin B complex formulations and added to supplements and fortified foods such as cereals. An adequate supply of vitamin B12 is essential to maintain healthy nerve cell and red blood cell function, as well as for folate utilization 1 and for normal protein, fat and carbohydrate metabolism 2.
Blood levels of vitamin B12 tend to decline with age 2, and individuals with lower blood levels may be at greater risk of cognitive decline 4. Higher levels of intake of have been associated with improved cognitive function in elderly subjects 5,6,7.
No adverse effects have been associated with vitamin B12 intake from food or supplements in healthy individuals 1. The U.S. Food and Drug Administration (FDA) has established a Reference Daily Intake (RDI) of 6 μg vitamin B12 for adults and children 4 or more years of age (21CFR101.9). RDIs are a set of dietary references for essential vitamins and minerals that are considered amounts sufficient to meet the daily requirements of healthy individuals. RDIs serve as the basis for calculating the percent daily value (%DV) amounts found on dietary supplement and food labels.
Cyanocobalamin is the principal form of vitamin B12 for commercial use in fortified foods and dietary supplements. According to the FDA, cyanocobalamin is generally recognized as safe (GRAS) (21 CFR184.1945). Once absorbed through the intestine, it is converted to the active forms of vitamin B12 in the body.