Vitamin D status, vitamin D receptor, CYP2R1, and CYP24A1 profiles in children

Vitamin D plays a major role in the musculoskeletal and immune system. Understanding the comprehensive mechanism of vitamin D receptors and the enzyme of vitamin D induction (CYP2R1) and inhibition (CYP24A1) in its metabolism is interesting. This study aims to understand vitamin D metabolism in Indonesian pediatrics, specifically in Jakarta, which has abundant sun exposure.

A cross-sectional study with comparative, correlative, and multivariate analysis on vitamin D, vitamin D receptor, CYP2R1, and CYP24A1 levels was conducted on 46 children with no known morbidity.

Subjects were mostly male (52.2%), age group of 2-6 years (34.8%), and had sufficient vitamin D status (43.5%, median 27.55 ng/mL). Age was found to have a negative correlation with vitamin D levels (p < 0.001; r = -0.625) and CYP2R1 (p = 0.035; r = -0.311). Significant positive associations were found between CYP24A1 and CYP2R1 (p = 0.046; r = 0.296). Participants aged 0-2 are more likely to have a higher level of vitamin D status compared to those aged >2 years (OR 42.092, 95% CI [4.532-390.914], p = 0.001). VDR levels were significantly lower in insufficient vitamin D levels than in the sufficient group (p = 0.018). VDR and vitamin D status had a positive relation (OR 7.023, 95% CI [1.864-26.453], p = 0.004).

Vitamin D levels decrease with the increase in age. Vitamin D receptor level has an inline-level progression with vitamin D level. CYP2R1 and CYP24A1 suggest a directly proportional relationship. Vitamin D screening and supplementation in children older than 2 years old are suggested.