Vitamin D Status in Primary Hypothyroid Subjects Attending a Specialized Endocrine Center of Bangladesh

Abstract

Background: Association between vitamin D deficiency and hypothyroidism has been reported by many authors though the study results are mixed. Objective: The study was conducted to observe vitamin D status among primary hypothyroid subjects. Materials/Methods: In this single-center cross-sectional study, 356 subjects with primary hypothyroidism (either new or previously diagnosed) were evaluated for serum thyroid stimulating hormone (TSH) and 25(OH) vitamin D levels. 25(OH)D levels were classified as normal (≥30 ng/ml), insufficient (>20 to 29.9 ng/ml), and deficient (≤20 ng/ml). Results: The mean age of the study subjects was 36.33 (±12.44) years; majority of them were female (89.9%), homemaker (79.8%), residing in urban or suburban areas (64%), and literate (85.7%); almost half (48%) of them were obese. Their median TSH was 6.17 µIU/ml and mean 25(OH)D was 25.16 (±12.18) ng/ml. The frequencies of vitamin D deficiency and insufficiency were 39.6% and 34.3% respectively. No statistical differences were observed in 25(OH)D levels between males and females, obese and non-obese, new cases and previously diagnosed cases, new cases with subclinical and overt hypothyroidism, the previously diagnosed cases with controlled and uncontrolled hypothyroidism, and among subjects living in urban, suburban and rural areas. Serum 25(OH) vitamin D level showed no correlations with age, body mass index (BMI) and TSH levels of the study subjects. Conclusion: The observed frequency of hypovitaminosis D (deficiency and insufficiency) was high (73.9%) in primary hypothyroid subjects from Bangladesh.