25(OH)D3-enriched or fortified foods are more efficient at tackling inadequate vitamin D status than vitamin D3

摘要

The ability to synthesise sufficient vitamin D through sunlight in human subjects can be limited. Thus, diet has become an important contributor to vitamin D intake and status; however, there are only a few foods (e.g. egg yolk, oily fish) naturally rich in vitamin D. Therefore, vitamin D-enriched foods via supplementing the animals’ diet with vitamin D or vitamin D fortification of foods have been proposed as strategies to increase vitamin D intake. Evidence that cholecalciferol (vitamin Dsub3/sub) and calcifediol (25(OH)Dsub3/sub) content of eggs, fish and milk increased in response to vitamin Dsub3/sub supplementation of hens, fish or cows’ diets was identified when vitamin D-enrichment studies were reviewed. However, evidence from supplementation studies with hens showed only dietary 25(OH)Dsub3/sub, not vitamin Dsub3/sub supplementation, resulted in a pronounced increase of 25(OH)Dsub3/sub in the eggs. Furthermore, evidence from randomised controlled trials indicated that a 25(OH)Dsub3/sub oral supplement could be absorbed faster and more efficiently raise serum 25(OH)D concentration compared with vitamin Dsub3/sub supplementation. Moreover, evidence showed the relative effectiveness of increasing vitamin D status using 25(OH)Dsub3/sub varied between 3·13 and 7·14 times that of vitamin Dsub3/sub, probably due to the different characteristics of the investigated subjects or study design. Therefore, vitamin D-enrichment or fortified foods using 25(OH)Dsub3/sub would appear to have advantages over vitamin Dsub3/sub. Further well-controlled studies are needed to assess the effects of 25(OH)Dsub3/sub enriched or fortified foods in the general population and clinical patients.