Determinants of Vitamin D deficiency in asymptomatic healthy young medical students

Objective: The study aimed to determine vitamin D status and frequency of its determinants related to diet, clothing, lifestyle and exposure to sunlight among young healthy medical students living in Karachi, Pakistan. Methods: This cross sectional study included responses gathered on questionnaire from medical students of Karachi Medical & Dental College from 4th of August 2017 till 30th April 2018. All the participants were healthy young adult's year of age who gave written informed consent to participate in the study. Questions regarding demographics, sun exposure, diet, clothing, living patterns and any symptoms like pain or body aches were recorded. Serum 25 (OH) vitamin D3, calcium and phosphorus levels were measured through laboratory examination. For serum 250HD, the cutoff values <= 20ng /ml, >= 21-29ng /ml, and >= 30ng/ml were defined as deficiency, insufficiency, and sufficiency respectively. Results: Total number of medical students enrolled in the study was 221. Among total participants 191 (86.43%) were females and 30 (13.57%) were males. Mean +/- SD age was almost similar (23.00 +/- 2.56 vs. 23.03 +/- 2.05). Majority of the females 115 (60.2%) had BMI within normal range, and were predominantly single 164 (85.9%). Vitamin D deficiency was found in 197 (89.14%), insufficiency in 16 (7.24%), and only 8 (3.62%) had sufficient levels. Determinant factors reported by deficient group (n=197); fabric color (dark mix) 87.3%, fabric material (synthetic + mix) 48.7%, full length of sleeves by 45.7%, exposure to sun only on hands and face during outdoors was reported by 64.5%, milk up to 250 cc was consumed by 77.2%, one egg per day in diet was taken by 56.9% and intake of cod liver oil was less common in only 27.4%. Conclusion: Deficiency of vitamin D is common among healthy young adults particularly females which emphasize need to add vitamin D supplements in their routine diet.