Assessing the effect of dietary calcium intake and 25 OHD status on bone turnover in women in Pakistan.

Summary: Bone health assessed in three towns of Karachi, Pakistan in females showed poor calcium intake, vitamin D deficiency, secondary hyperparathyroidism, and high bone turnover. Correlates of high bone turnover included females residing in Saddar Town, underweight females less than 30 years of age from low socio-economic status, and secondary hyperparathyroidism.

Aims: To assess bone health and association of dietary calcium and 25 hydroxy vitamin D with bone turnover in the community-dwelling females of Karachi.

Methods: Bone health was assessed in three randomly selected towns of Karachi, Pakistan. One premenopausal female fulfilling the inclusion criteria from each household was included in the study. Dietary calcium was assessed through a food frequency questionnaire and biochemical markers including calcium, phosphates, albumin, magnesium, creatinine, and SGPT, intact parathyroid hormone, 25 hydroxy vitamin D, and N-telopeptide of type I collagen were measured to assess the bone health.

Results: Three hundred and five females were included from three towns. Overall, 90.5% of females had vitamin D deficiency with 42.6 and 23.3% having secondary hyperparathyroidism and high bone turn over respectively. Prevalence of vitamin D deficiency, secondary hyperparathyroidism, and high bone turnover was significantly different among towns. Mean vitamin D levels were significantly low and iPTH levels significantly high in females with high bone turnover. Calcium intake was not significantly different among females with normal, high, and low bone turnover. Correlates of high bone turnover included females residing in Saddar Town, underweight females less than 30 years of age belonging to low socio-economic status, and secondary hyperparathyroidism.

Conclusion: Compromised bone health is seen in community-dwelling females of Karachi. There is a need to perform large-scale community-based studies in all age groups to understand the interplay of markers in our population to understand the impact of these variables translating into the risk of osteoporosis.