Dose-response relationships regarding vitamin B-6 in elderly people: a nationwide nutritional survey (Dutch...

The dietary intake and biochemical status of vitamin B-6 in 476 apparently healthy Dutch elderly people (aged 65-79 y), who were not using drugs known to affect vitamin B-6 metabolism, were evaluated. Intake of vitamin B-6 per gram protein was related to biochemical data, namely plasma pyridoxal 5'-phosphate (PLP) and cofactor stimulation of aspartate aminotransferase in erythrocytes (AST-AC). Based on a cutoff point of 2.02 for AST-AC, approximately 9% of the elderly people not using vitamin B-6 supplements had a marginal vitamin B-6 status. About 7% were using vitamin B-6 supplements. Dietary intake of vitamin B-6 per gram protein was negatively related to AST-AC. Vitamin B-6 intakes per gram protein higher than 0.020 mg were necessary to ensure an AST-AC value less than 2.02. At high PLP values AST-AC hardly varied. The results seem to indicate a higher requirement of vitamin B-6 in elderly people than in younger adults.