Vitamin B12 deficiency in Australian residential aged care facilities.

Abstract

To determine the prevalence of undiagnosed vitamin B12 deficiency among residential aged care facility residents in southern Tasmania, Australia, and to identify associated risk factors. Cross-sectional study of residents from five southern Tasmanian residential aged care facilities. Two hundred and fifty-nine residents without a prior diagnosis of vitamin B12 deficiency or recorded serum B12 level within the past 6 months were approached to have their serum B12 level tested. One hundred and sixty (61%) residents consented and their doctors were contacted for further consent. A total of 130 (50%) residents completed the study. Clinical and demographic characteristics, and serum B12 level. Of the 130 residents tested, 18 residents (14%) were considered vitamin B12 deficient (serum level <150 pmol/L), 47 (36%) were equivocal (150 pmol/L to 250 pmol/L) and 65 (50%) had normal serum B12 levels (>250 pmol/L). There was a weak negative correlation between age and serum B12 level in those residents not taking a multivitamin (n=120, r=-0.19, p<0.05). The use of a multivitamin or antipsychotic drug were associated with altered mean serum B12 levels (+137 pmol/L, p<0.001 and -70 pmol/L, p<0.001 respectively). As vitamin B12 deficiency can manifest in a range of symptoms that are frequently misdiagnosed, the finding of undetected deficiency in 14% of residents is a cause for concern. Oral multivitamin supplementation may help prevent deficiency, and potentially treat existing deficiencies in older institutionalised people.