Association between organochlorine pesticides and vitamin D in female subjects

In human population studies, organochlorine pesticides (OCPs) have been linked to vitamin D deficiency. Therefore, this study examined the association between OCPs, vitamin D3 (cholecalciferol, 25(OH)D3), and the active metabolite 1,25-dihydrovitamin D3 (1,25(OH)2D3) in a cohort of non-obese women. The serum samples of 58 female participants (age-31.9 ± 4.6 years; body mass index (BMI)-25.7 ± 3.7 kg/m2) were screened for 10 indicator OCPs. 25(OH)D3 and 1,25(OH)2D3 levels were determined via isotope dilution liquid chromatography tandem mass spectrometry. In this cohort, the 25(OH)D3 and 1,25(OH)2D3 levels were 22.9 ± 11.2 ng/mL and 0.05 ± 0.02 ng/mL, respectively, with 28 participants classified as 25(OH)D3-deficient (<50 nmol/L). In the study cohort, no correlations were found between individual or total OCPs (ƩOCPs) and 25(OH)D3. p,p'-dichlorodiphenyldichloroethylene (DDE) and ƩOCPs correlated positively with 1,25(OH)2D3, with the latter being negatively correlated with estimated glomerular filtration rate (eGFR). In women with sufficient 25(OH)D3 levels, p,p'-dichlorodiphenyltrichloroethan (DDT) was positively correlated with 1,25(OH)2D3, whilst in the deficient group, hexachlorobenzene (HCB) and p,p'-(DDE) were positively correlated with 1,25(OH)2D3, β-Hexachlorocyclohexane (HCH) was positively correlated with 25(OH)D3, and none of the OCPs were associated with measures of renal function. Overall, OCPs and ƩOCPs were not associated with 25(OH)D3, suggesting that they are unrelated to vitamin D deficiency, but p,p'-DDE and ƩOCPs correlated positively with active 1,25(OH)2D3, while ƩOCPs correlated negatively with eGFR, suggesting a possible renal effect. Analysis of vitamin D deficiency revealed an association between β-HCH and 25(OH)D3, and between HCB and p,p'-DDE and 1,25(OH)2D3, suggesting that OCP effects may be enhanced in cases of vitamin D deficiency.