Study of the Possible Effect of Obesity on Vitamin D Level among a Sample of Adult Men in the Western Region of Kingdom of Saudi Arabia
Ayman Zaky Elsamanoudy *
Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University (KAU), Saudi Arabia and Department of Medical Biochemistry and Molecular Biology, Mansoura University, Egypt
Mohammed Hassanien
Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University (KAU), Saudi Arabia and Department of Medical Biochemistry, Faculty of Medicine, Tanta University, Egypt
Maher Mohamed Khayyat
Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University (KAU), Saudi Arabia
Mohammed- Saleh Mohamed Ardawi
Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University (KAU), Saudi Arabia and Center of Excellence for Osteoporosis Research, King Abdulaziz University, Saudi Arabia
*Author to whom correspondence should be addressed.
Abstract
Aim of the Study: This cross sectional study was aimed to investigate the effect of obesity on vitamin D levels in adult male in the western region of Saudi Arabia.
Study Design and Methods: One hundred twenty two Healthy men, aged 20–45 years are included in this study. They were divided into normal (n=48), overweight (n=26) and obese (n=48), according to their body mass index (BMI). Serum 25[OH]D, parathyroid hormone (PTH) and calcium were measured in different BMI groups. We also measured total body fat percentage (TBF%) and bone mineral density (BMD) in Spine (L1–L4), Femur Neck and Total Body, by DXA technique.
Results: Of the total participants, 94.9% had vitamin D deficiency with a mean 27.6±10.78 nmol/L (normal level; 75-250 nmol/L). The mean serum levels for 25(OH)D for the normal, overweight and obese groups were 28.7±12.16 nmol/L, 27.0±8.71 nmol/L and 27.0±10.43 nmol/L, respectively. Of the total participants, 89.4% had an above-average TBF%, and it was negatively correlated with serum 25(OH)D. Serum calcium was significantly lower in the obese group compared with the normal BMI group (P<0.001). Serum PTH was significantly higher in the obese group compared with the normal BMI group (P<0.023). The BMI was significantly positively correlated with the different BMD measurements. Of our participants, 62% were physically inactive and only 14% were exposed to sunlight.
Conclusion: The prevalence of vitamin D deficiency in Saudi Arabian men is high, regardless of differences in BMI. Elevations in TBF% in different BMI categories play an important role in elevated vitamin D deficiency rates. A sedentary lifestyle and elevated adiposity contribute to an elevation in the vitamin D deficiency rate.
Keywords: vitamin D, Body mass index, bone mineral density, obesity