Frail elderly people are particularly at risk for nutritional deficiencies that can contribute to cardiovascular disease, functional decline and neurological disorders. Moderately increased homocysteine (Hcy) and methlylmalonic acid (MMA) are markers of folate, vitamin B6 or B12 deficiency. In a study published in the American Journal of Clinical Nutrition, de Jong et al. conducted a series of controlled interventions to determine if supplementation with nutrient-dense foods, an exercise program, or a combination of the two would benefit elderly subjects' nutritional status and neurological functioning. Food enrichment seemed to offer the most tangible health benefits by lowering serum concentrations of Hcy and MMA. Yet supplementation with nutrient-dense foods produced no improvement in the subjects' test scores on neuropsychological functioning, and the exercise program had no effect on indexes of nutritional health, whether it was combined with supplementation or not.