“…Consistent with these findings, several human studies have also reported an association between vitamin D and YLK-40. Can et al 8) reported that plasma YKL-40 levels were significantly lower in subjects with vitamin D deficiency compared to age and sex-matched healthy subjects. In another study, Omidian et al 9) showed that vitamin D supplementation significantly reduced serum YKL-40 levels in type 2 diabetic patients.…”