Vitamin B12 (2)Hans R. LarsenVitaminB12 Deficiency: Incidence and ConsequencesVitamin B12 deficiency easy to avoidKINGSTON, CANADA. Many older people suffer from a deficiency of
Vitamin B12(
cobalamin). A low intake of animal protein, the use of medications to reducestomach acid, a Helicobacter pylori infection, an inflammation of the stomachlining, and problems with the pancreas can all contribute to the development ofa deficiency. Replacing the metformin with sulfonylurea and taking 1000 mg ofcyanocobalamin (vitamin B12) for two months reversed the deficiency. A detailedstudy of 138
patients with vitamin B12 deficiency and anaemia discovered that77 (58 per
cent) of the patients had a H pylori infection. Eradicationof this infection successfully cured the anaemia and reversed the vitamin B12deficiency in 31 (40 per cent) of the 77 infected patients. The average age ofthe ministers was 46 years (range 22 to 80 years) and most of them had beenvegetarians for over 20 years. The researchers determined vitamin B12concentrations in blood samples obtained in 1974 and in 1989 and compared thelevels found in 195 women who later developed breast cancer with the levelsfound in 195 women free of cancer. They found that postmenopausal women withthe lowest
serum levels of vitamin B12 had a 2.5-4.0 times greater likelihoodof being in the breast cancer group than did women with the highest levels. Theresearchers found no correlation between breast cancer risk and serum levels offolic acid, vitamin B6, and homocysteine. A prospective study of folate,B12, and pyridoxal 5'-phosphate (B6) and breast cancer. She also cautionsthat the blood level of cobalamin is an unreliable indicator of deficiency andthat tissue levels of the vitamin may be quite low even though the blood levelsare normal. The best test of cobalamin deficiency involves measuring the bloodlevels of homocysteine and methylmalonic acid. If the level of these twoprecursors to the metabolic reactions controlled by cobalamin are high then thevitamin B12 level is low. Vitamin B12 deficiencies may be treated by injectionsof the vitamin or by oral supplementation. Analysis of blood serum showed that11 per cent of the participants were deficient in cobalamin (vitamin B-12). Theresearchers discovered several cases of gastritis (inflammation of the liningof the stomach) and two cases of celiac disease among patients with low serumvalues of cobalamin. Theyconclude that routine screening for a vitamin B-12 deficiency isjustified in the case of older people. In a separate letter to the Journal of the American GeriatricsSociety doctors from the Union Memorial Hospital in Baltimore report on acase of vitamin B-12 deficiency. Although his serum level of vitamin B-12 waswithin the currently accepted range, the doctors decided to proceed withvitamin B-12 therapy. The doctors conclude that the levels of serum vitaminB-12 concentrations currently considered normal in the United States may be toolow and should be reassessed. The lower limit of 200 pg/mL is based on thelevel that causes abnormalities in the blood (pernicious anaemia). Prevalenceand diagnosis of cobalamin deficiency in older people. Journal of the AmericanGeriatrics Society, Vol. 44, No. The researchers found that 31 per cent ofthe surgery group had a vitamin B-12 deficiency as compared to 2 per cent amongthe controls. The presence of a deficiency was established through measurementsof the levels of vitamin B-12, total homocysteine, and methylmalonic acid inthe blood. The deficiencies were corrected by daily injections of 1000micrograms of vitamin B-12 for five days followed by monthly injections. Theyfound that 40.5 per cent of the
elderly people suffered from a vitamin B12deficiency versus only 17.9 per cent in the younger group. The researchers alsopoint out that a vitamin B12 deficiency leads to an accumulation ofhomocysteine in the blood. Prevalence of cobalamin deficiency in theFramingham elderly population. Vitamin B-12 deficiencin elderly individuals:diagnosis and requirements. The researchers measured the blood concentrations ofthe vitamins in all subjects as well as the concentration of certain metabolicproducts that tend to build up if a vitamin deficiency is present. Correspondingnumbers for vitamin B-12 and folic acid were 6% and 5%, and 5% and 19%respectively. Of perhaps greater significance was the finding that in 63% ofthe healthy elderly subjects and in 83% of the elderly patients the researchersobserved an increased serum concentration of one or more of the metabolicproducts that indicate a deficiency in vitamin B-6, B-12 or folate. Thus anelevated level of the metabolite (methylmalonic acid), which indicates a B-12deficiency, was found in 23% of the healthy elderly people and in 39% of theelderly hospitalized patients. Recent experiments have shown that weeklyinjections of vitamin B-12, B-6, and folate are highly effective in normalizingthe elevated metabolite concentrations in elderly people.Metabolic evidence that deficiencies of vitamin B-12 (cobalamin), folate,and vitamin B-6 occur commonly in elderly people. 3,September 1993, pp. 468-76