Correlation of Vitamin D Deficiency with Levels of Calcium and Phosphate in the Adult Population of Khairpur Mir's.

Abstract

Objective: To determine the correlation between vitamin D level and serum calcium and phosphate in the adult population
of Khairpur Mir's, and to identify independent predictors of vitamin D deficiency.
Methodology: This cross-sectional study enrolled 210 asymptomatic adults aged 20-39 years from Khairpur Mir's. Serum
vitamin D, calcium, and phosphate were measured biochemically, and demographic and lifestyle data were recorded.
Vitamin D deficiency was defined as <20 ng/mL. Associations were assessed using chi-square and independentsamples
t-tests; independent predictors of deficiency were identified using univariate and multivariable binary logistic
regression; and the vitamin D-calcium and vitamin D-phosphate relationships were quantified using Pearson's and
Spearman's correlation coefficients.
Results: Mean serum vitamin D was 19.54±8.00 ng/mL; 53.3% of participants were deficient. Mean calcium was
8.75±0.98 mg/dL (36.7% deficient) and mean phosphate was 3.31±0.73 mg/dL (32.4% deficient). Vitamin D correlated
moderately with calcium (r=0.451, p<0.001) but only weakly and non-significantly with phosphate (r=0.125, p=0.071). On
multivariable logistic regression, employment (adjusted OR=4.52, 95% CI 2.41-8.48, p<0.001) and inadequate sun exposure
(adjusted OR=4.41, 95% CI 2.32-8.40, p<0.001) were independent predictors of vitamin D deficiency; age, sex,
education, and dietary intake were not.
Conclusion: Vitamin D deficiency is common among adults in Khairpur Mir's and correlates significantly with serum calcium
but not phosphate, consistent with their differential regulation. Employment and inadequate sun exposure, rather
than demographic factors, independently predict deficiency, supporting targeted, exposure-based screening and supplementation
strategies for this and similarly under-studied districts.
Keywords: Vitamin D deficiency; Calcium; Phosphate; Correlation; Khairpur Mir's; Pakistan.