Background – Malnutrition is common in the elderly. Vitamin B12 is of particular interest as deficiency is linked to chronic diseases including dementia, osteoporosis, stroke and macular degeneration.
Objective – To examine the extent and determinants of malnutrition, including micronutrient deficiencies in an aged care rehabilitation unit.
Design – Patients (n=67, age >60 y) admitted to Calvary Health Care Sydney, underwent screening using the Mini Nutritional Assessment (MNA) and a modified MNA (mMNA) incorporating Australian protein and anthropometric indices. Biochemical screening assessed protein and micronutrient status. A sub-group of patients (n=22) underwent additional investigations to determine vitamin B12 status, as assessed by methylmalonic acid (MMA) and homocysteine concentrations, and dietary intake using a semi-quantitative food frequency questionnaire (FFQ). Outcomes – Eighteen and 27% of patients were malnourished as determined by the MNA and mMNA, respectively, with both tools indicating 61% of patients were at risk of malnutrition. Twenty-six subjects (38%) were deficient in vitamin B12 (based on values <220 pmol/L) and 53 subjects (79%) were deficient in vitamin D (<50 nmol/L). A positive correlation was found between serum folate concentrations and the mMNA score (r= +0.28, P<0.05). Hyperhomocysteinemia (>12 μmol/L) was found in 73% of subjects (n=16), and was significantly associated with lower serum- and erythrocyte-folate concentrations. Thirty-six percent (n=8) of subjects had elevated MMA indicating cellular vitamin B12 deficiency, but all had serum vitamin B12 in the normal range. All subjects had adequate intakes (>77% 1991RDI) of vitamin B6, B12 and folate.
Conclusions – The present study highlights malnutrition, vitamin D and vitamin B12 deficiencies in subjects with normal serum vitamin B12 levels. This study supports routine screening and appropriate supplementation of micronutrients.