Figure 7.

Plasma response of B₃ vitamers, (A), nicotinic acid (B), nicotinamide, and (C), nicotinuric acid at baseline (fasting, time, 0), hourly until four hours (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. Data for multiple time points was compared using general linear mixed model with time as repeated and age as fixed factors. AUC data was compared with general linear univariate analysis of variance with age as fixed factor. *, p < 0.05; ***, p < 0.001, significant change following supplement intake relative to baseline in both age groups. No significant difference in postprandial change between the age groups. Nicotinic acid concentration did not increase compared to baseline (time effect, p = 0.370), whereas nicotinamide increased (time effect, p < 0.001) with lower concentration in older than the younger adults (age effect α, p = 0.038) and nicotinuric acid decreased continuously throughout the 4-h postprandial period (time effect, p = 0.002).