Figure 3.

Plasma response of B₆ vitamers at fasting (time, 0), hourly until 4 h (time, 1, 2, 3, 4) and the four hour incremental area under the curve (AUC, represented by bar-graphs) following a single multivitamin and mineral supplement ingestion in older and younger adults. (A), Pyridoxine (B), pyridoxal (C), pyridoxamine (D), pyridoxal 5′-phosphate (PLP), and (E) 4-pyridoxic acid. Data for multiple time points was compared using general linear mixed model with time as repeated and age as fixed factor. AUC data was compared with general linear univariate analysis of variance with age as fixed factor. Sidak post hoc test was applied for pairwise comparisons if significant interaction was present. ***, p < 0.001, significant increase following supplement intake relative to baseline in both age groups. The older adults had decreased postprandial increase in pyridoxine (age effect p < 0.035, time effect p < 0,001) and PLP (age effect p = 0.009, time effect p < 0.001) but increased 4-pyridoxic acid (age × time, p = 0.002) than the younger adults (α, p < 0.05; β, p < 0.01; γ, p < 0.001, main age difference or difference with age × time interaction at particular time points).