Vitamin D Supplementation improves Bone Mineral Density in Patients with Hyperthyroidism

Background: Diseases of the thyroid gland are a common occurrence in India. Thyrotoxicosis causes acceleration of bone remodeling and even though it is one of the known risk factors for osteoporosis, the metabolic effects of thyroxine on bone is a little- discussed subject. Materials & Methods: 70 consecutive patients with hyperthyroidism attending endocrine clinic of Maulana Azad Medical College. Serum total calcium, phosphorous, urinary creatinine and alkaline phosphatase were measured by standard methods. Serum T4, serum 25(OH)D estimations were done by radioimmunoassay assay. Serum intact PTH and TSH concentration was measured by immune-radiometric assay using commercial kits. Bone mineral density was measured using Hologic DR 4500A densitometer. Bone mineral density was measured at both hips, and lumbar spine (L2-L4) using anteroposterior view. 50% of the patients were randomized for vitamin D supplementation. Results: The mean age of the patients was 39±10.01 years. The baseline vitamin D of the patients was 19.24±10.15 ng/ml. The values of vitamin D in randomized and non-randomized patients were 27.82±16.43 vs 11.82±6.58 ng/ml (p>0.0001) respectively. Patients who received vitamin D had acquired optimum level of vitamin significantly, whereas, BMD at lumbar spine was also found increased after post treatment of vitamin D. However, it was not significantly raised when compared with the pre treatment. BMD at hip region was found elevated after post-treatment. There was an improvement noticed in total body BMD as well. Conclusion: Patients with active thyrotoxicosis, acquired optimum vitamin D levels, elevated lumbar spine and hip BMD after one year of vitamin D supplementation. Vitamin D supplementation is necessary to be advocated in patients with hyperthyroidism.