Associations of bone health biomarkers and bone mineral density with dietary intakes in vitamin D deficient women: a cross-sectional study

Vitamin D, an essential nutrient for bone health, is widely deficient in India despite abundant sunlight. The prevalence ranges between 70 and 90% in adult women. We studied the prevalence of vitamin D deficiency/insufficiency and the association between serum 25-hydroxyvitamin D, parathyroid hormone, osteocalcin, bone-specific alkaline phosphatase, bone mineral density, and dietary intakes in young urban women. Among 220 women screened, 84.7% of participants had suboptimal vitamin D (64.5% deficient 20.2% insufficient). In 108 vitamin D deficient women, 75% reported below 15 min of daily sun exposure. Dietary calcium intake was 480.6 ± 117.7 mg/day. Serum 25(OH)D was negatively correlated with PTH (⍴ = - 0.364, p < 0.001) and osteocalcin (⍴ = - 0.342, p < 0.001). Osteocalcin was positively correlated with dietary calcium (⍴ = 0.228, p < 0.01), Ca: P (⍴ = 0.240, p < 0.01) and milk intake (⍴ = 0.226, p < 0.01). Positive associations were observed between osteocalcin and Ca: P ratio [β = 23.58, 95% CI: -0.614 to 47.771, p = 0.056] and with milk intake [β = 0.03, 95% CI: -0.001 to 0.065, p = 0.058]. The coexistence of vitamin D deficiency with inadequate calcium intake, and limited sun exposure, underscores the importance of strategies to promote calcium-rich diets and adequate sunlight practices to support bone health.