Serum 25-Hydroxyvitamin D in relation to Parathyroid Hormone, and Calcium Intake in Saudi Premenopausal Women
Introduction: No information is available on dietary calcium intake among Saudi premenopausal women in relation to vitamin D status.Thus, the objective of the present study is to assess the inter- relations between dietary calcium intake, 25-hydroxyvitamin-D [25(OH)D] and PTH among Saudi healthy premenopausal women.
Subjects and Methods: A total of 138 Saudi healthy premenopausal women living in the Jeddah area were studied. Each woman completed a questionnaire on life-style factors, anthropometric data and dietary calcium intake. Fasting blood samples were collected for the measurements of serum 25(OH)D, parathyroid hormone (PTH), calcium, phosphate and magnesium. Bone mineral density (BMD) was measured by a dual-energy X-ray absorptiometry.
Results: All women showed vitamin-D deficiency (serum 25(OH)D < 50 nmol/L). Stratifying women by tertiles of daily dietary calcium intake showed that women with the lowest tertile exhibited significantly lower serum 25(OH)D (P<0.026), as compared with the group with the highest tertile. Stepwise multiple linear regression analysis showed that changes in serum 25(OH)D contributed to the variation in daily dietary calcium intake.
Conclusions: Vitamin-D deficiency is common among Saudi healthy premenopausal women and such was associated with low daily dietary calcium intake.