SEASONAL-VARIATION OF VITAMIN-A (RETINOL) STATUS IN OLDER MEN AND WOMEN

Objective: The present study was undertaken to determine vitamin A sta tus in 59 free-living (26 males, 33 females) healthy older persons (65 -74 years) in winter and summer. Design: Three-day dietary intake data for vitamin A along with carbohydrate, lipid and protein were collect ed during the summer (June - September) and again during the winter (N ovember - March). In addition, retinol and its carrier proteins, retin ol-binding protein (RBP) and transthyretin (TTR), were measured in the plasma in each season. Results: The mean vitamin A intake met the Can adian Recommended Intake (RNI) for both gender and season. However, pr obability analysis of dietary data revealed that 7 and 11% of males, a nd 8 and 14% of females, in summer and winter, respectively, were at r isk of deficiency. None of the subjects in the present study exhibited biochemical evidence of vitamin A deficiency as determined by plasma levels of retinol and its transport proteins. Overall, the mean intake of vitamin A was significantly higher in males than in females; no se asonal effect was observed. On the other hand, the plasma levels of re tinol and its carrier proteins were significantly lower in winter seas on than in summer, without any gender variation effect. Conclusion: Al though mean values for dietary intake and plasma concentration of vita min A may indicate nutritional adequacy, a small proportion of an olde r population may be at nutritional risk. The prevalence of risk appear s to be generally higher in the winter than in the summer season and i n females than in males.