KINGSTON, CANADA. Many older people suffer from a deficiency of vitamin B12 (cobalamin). A low intake of animal protein, the use of medications to reduce stomach acid, a Helicobacter pylori infection, an inflammation of the stomach lining, and problems with the pancreas can all contribute to the development of a deficiency. Medical researchers at Queen’s University now report that daily supplementation with a multivitamin containing 2.6 – 37.5 micrograms of vitamin B12 is enough to prevent a cobalamin deficiency in most older healthy people. Their study involved 242 active, relatively healthy men and women aged 65 years or older. Sixty-six (27.3 per cent) of the volunteers had been taking a daily multivitamin containing 2.6 – 37.5 micrograms of vitamin-B12 for at least six months.
All volunteers had blood samples drawn for the measurement of cobalamin level as well as the levels of the related metabolites methylmalonic acid (MMA), homocysteine (HCYS) and methylcitric acid (MCTR). Thirty- seven (15.3 per cent) of the 242 participants were deficient in cobalamin (level below 165 pmol/L). Of these 37 only 2 were taking multivitamins. An elevated level of MMA was found in 53 participants of whom 46 (87 per cent) were not taking multivitamins. An elevated level of homocysteine was found in 17 participants of whom 16 were not supplementing. The researchers conclude that oral supplementation with 25 micrograms/day or higher may be sufficient to prevent vitamin B12 deficiency in a large proportion of older people. They caution though that their findings cannot be extrapolated to frail or sick old people who may require larger doses to avoid deficiency.
Garcia, Angela, et al. Is low-dose oral cobalamin enough to normalize cobalamin function in older people? Journal of the American Geriatrics Society, Vol. 50, August 2002, pp. 1401-04