Original Research Article http://doi.org/10.18231/j.ijcbr.2019.057 International Journal of Clinical Biochemistry and Research, April-June, 2019;6(2):255-258 255 Evaluating correlation between Vitamin D levels and hypothyroidism: A pilot study Angie Garg 1 , Amandeep Kaur 2* , Bhavneet Singh 3 , Sahiba Kukreja 4 1,3 Final Year Student, 2 Associate Professor, 4 Professor and Head, 2,4 Dept. of Biochemistry, 1-4 Sri Guru Ram Das Institute of Medical Sciences and Research Amritsar, Punjab, India *Corresponding Author: Amandeep Kaur Email: amandeepbest@gmail.com Abstract Vitamin D deficiency is very common worldwide. Vitamin D has steroid like properties being produced in skin and regulates the expression of various genes. Its main biochemical role is in the regulation of bone metabolism by regulation of calcium and phosphorus levels in the body. Vitamin D has non-skeletal functions also like immunomodulation and anti-inflammation which could be the reason behind the pathogenesis of thyroid diseases. Several studies have proved the role of vitamin D in the pathogenesis of various diseases like autoimmune diseases, infectious diseases, heart diseases, metabolic syndrome as well as cancer. Considering this potential role, this study was done with the aim of assessing Vitamin D levels and correlation of these levels of vitamin D with thyroid profile in patients of hypothyroidism. Keywords: Vitamin D, Hypothyroidism, Thyroid profile, Autoimmune thyroid disease, Vit D deficiency. Introduction Hypothyroidism is one of the most common endocrine disorders. In past, the most primary cause of hypothyroidism was iodine deficiency; however, with the introduction of iodized salt, its incidence was reduced in the industrialized nations. The prevalence of hypothyroidism in developed countries is about 4%-5%, whereas in India, it is reported to be around 10.95%. As per the epidemiology study conducted by Unnikrishnan et al, in eight cities of India, the prevalence of subclinical hypothyroidism, a mild thyroid failure was found to be 8.02%. The prevalence of subclinical hypothyroidism ranges between 4%-15% worldwide and is reported to be 11.4% for women and 6.2% for men in India. 1 In areas where iodine sources are sufficient, autoimmune hypothyroidism is more common than iodine deficient thyroid diseases. Hashimoto’s thyroiditis is a hereditary disorder mostly seen in middle aged US population. Most of the Hashimoto’s thyroiditis patients (90-100%) have presence or high levels of anti thyroid antibodies. In India autoimmune hypothyroidism is the most frequent endocrine disorder affecting more than 42 million people. 2 Intrathyroidal lymphocytic infiltration is followed by a gradual destruction of the thyroid gland which may lead to subclinical or overt hypothyroidism. Biochemical markers of the disease are thyroid peroxidase and/or thyroglobulin autoantibodies in the serum. Vitamin D and thyroid hormone bind to similar receptors called steroid hormone receptors. A different gene in Vitamin D receptor was shown to predispose people to autoimmune thyroid diseases including Grave’s disease and Hashimoto’s thyroiditis. 3 Previously, it has been considered that vitamin D deficiency was rare in India because of enough exposure to sunshine. A study carried out in Delhi on study population included newborns and their mothers, health care workers, soldiers and patients of albinism and vitiligo presented with 25-hydroxy vitamin D (25(OH) D) insufficiency or deficiency. 4 Based on these study groups, subnormal serum 25(OH) D levels of Asian Indians could be linked to their skin pigmentation and poor sunshine exposure. Studies assessing the association between autoimmune thyroid disease & vitamin D levels have produced conflicting results. 5-8 In India, few studies had done to explain the relationship between vitamin D levels & thyroid autoimmunity. Considering the high prevalence of thyroid autoimmunity and vitamin D deficiency in the Indian population it arises a need to assess the relationship between these two diseases. So, the present study was conducted with the aim to estimate the levels of vitamin D in patients with hypothyroidism and to correlate the levels of vitamin D with thyroid profile in these patients Materials and Methods This cross sectional observational pilot study was conducted in the Department of Biochemistry in collaboration with the Department of Medicine, in a Tertiary Care Hospital. After taking prior ethical clearance by the institutional ethical committee, the study was conducted from 1 st June, 2017 to 31 st July, 2017. Hypothyroid patients in the age group of 21-50 years of either sex that visited Medicine OPD during this period were included in the study after their informed consent. The patients with clinical history and laboratory investigations suggestive of hypothyroidism with TSH values > 4.68 mIU/ml were included in the study. The patients with post radio–iodine hypothyroidism, liver disorders, renal disorders or primary hyperparathyroidism, those on anti- epileptic medication or vitamin D supplementation were excluded from the study. Sample Collection After 12 hours of fasting, venous blood sample was collected under aseptic conditions and processed within 24 hours for the following parameters: