The effects of vitamin D fortified products on bone biomarkers: A systematic review and meta-analysis

Background: Several studies suggest that vitamin D plays an essential role in the regulation of bone metabolism. The aim of the current meta-analysis was to assess the effectiveness of vitamin D fortification on special bone biomarkers.Methods: Five main databases (PubMed/Medline, ISI Web of Knowledge, Science Direct, Scopus, Cochrane Library as well as Science Direct, and Scopus) were considered for this systematic review, until January ۲۰۲۰. All randomized controlled trials were included to evaluate the probable relationship between consumption of vitamin D fortification products and bone biomarkers profile in this review.Results: Among serum bone biomarkers (osteocalcin and telopeptides of type-۱ collagen) investigated, only the level of telopeptides of type-۱ collagen significantly decreased after fortification of vitamin D in the intervention group. The significant increase in vitamin D was seen in those older than ۱۸ years old, while the increase in younger children was not statistically significant between intervention and control groups.Conclusion: Vitamin D fortification was not associated with a significant improvement in BMD, while it resulted in decreased PTH levels. Vitamin D fortified foods have some benefits on bone health due to increase in the level of vitamin D and IGF-۱; and decreasing PTH and CTx levels.

Keywords:

vitamin D , fortification , bone biomarkers , BMD , telopeptides of type-۱ collagen , osteocalcin , PTH , IGF-۱