Open Access Maced J Med Sci electronic publication ahead of print, published on March 19, 2017 as https://doi.org/10.3889/oamjms.2017.029 _______________________________________________________________________________________________________________________________ Open Access Maced J Med Sci. 1 ID Design 2012/DOOEL Skopje, Republic of Macedonia Open Access Macedonian Journal of Medical Sciences. https://doi.org/10.3889/oamjms.2017.029 eISSN: 1857-9655 Basic Science No Association between 25 (OH) Vitamin D Level And Hypothyroidism among Females Imad R. Musa 1 , Gasim I. Gasim 2* , Sajjad Khan 3 , Ibrahim A. Ibrahim 4 , Hamdi Abo-alazm 4 , Ishag Adam 5 1 Armed Forces Hospital at King Abdu Aziz Air Base, Dhahran, Saudi Arabia; 2 Alneelain School of Medicine, Alneelain University, Khartoum, Sudan; 3 Central Hospital, Arar, Saudi Arabia; 4 Medical Laboratory Science, United Medical Laboratory, Saudi Arabia; 5 Faculty of Medicine, Khartoum University, Khartoum, Sudan Citation: Musa IR, Gasim GI, Khan S, Ibrahim IA, Abo- alazm H, Adam I. No Association between 25 (OH) Vitamin D Level And Hypothyroidism among Females. Open Access Maced J Med Sci. https://doi.org/10.3889/oamjms.2017.029 Keywords: hypothyroidism; vitamin D levels; females. *Correspondence: Gasim I. Gasim. Alneelain School of Medicine, Alneelain University, Khartoum, Sudan. E-mail: gasimgsm@yahoo.com Received: 26-Nov-2016; Revised: 16-Jan-2017; Accepted: 09-Feb-2017; Online first: 19-Mar-2017 Copyright: © 2017 Imad R. Musa, Gasim I. Gasim, Sajjad Khan, Ibrahim A. Ibrahim, Hamdi Abo-alazm, Ishag Adam. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial 4.0 International License (CC BY-NC 4.0). Funding: This research did not receive any financial support. Competing Interests: The authors have declared that no competing interests exist. Abstract AIM: The aim was to investigate serum vitamin D (25-OH) level among females with hypothyroidism. MATERIALS AND METHODS: A case-control study (58 in each arm) was conducted in Arar Central Hospital, Kingdom Saudi Arabia. The cases were females with hypothyroidism, and healthy females were controls. TSH, thyroid hormones: Free T3 (FT3) and Free T4 (FT4) and haemoglobin levels were measured in all participants. Serum vitamin D (25-OH) level was measured using the spectrophotometry. RESULTS: While there was no significant difference in the age and haemoglobin level, body mass index (BMI) was significantly higher in the cases. Compared with the controls, cases had significantly higher TSH, had significantly lower T4, and there was no significant difference in FT3 and 25 (OH) vitamin D, [16.1 (8.8-26.7) vs. 14.0 (9.5-20.3 ng/ml; P = 0.577]. Linear regression showed no association between, age, BMI, haemoglobin, TSH, FT3, FT4 and the log of 25 (OH) vitamin D levels. CONCLUSION: There was no significant difference in vitamin D level among females with hypothyroidism and healthy controls. Introduction Vitamin D deficiency is a global health problem where over a billion people worldwide have some vitamin D deficiency or insufficiency [1, 2]. The essential biological action of vitamin D is the regulation of calcium and phosphorus metabolism. Though the role of vitamin D in the regulation of immune system has recently been reported [3, 4]. Hypothyroidism is a common disease in the general population, most of which results as consequences of Hashimoto's thyroiditis with a tendency to increase with age and female are at 8 to 15 times at higher risk than men [5]. It has been observed that serum Vitamin D3 metabolites are elevated in hypothyroid subjects [6]. However, a reduced level has been reported in a patient with over-active thyroid gland [7]. Thyroid disorders may affect vitamin D status as subnormal levels of vitamin D were observed in a patient with Graves' disease [8]. The role of vitamin D is explored as an anti-inflammatory, anti-proliferative factor and association with many clinical disorders [9, 10]. Vitamin D has a direct and indirect role in inhibiting the production of cytokines (IL-12 and IFN-c), hence, enhances the immune and anti-inflammatory responses [11]. Vitamin D is circulating in the blood attached to a D-binding protein. Then hydroxylation takes place at the liver and the kidneys to produce 25(OH) D and the active metabolite, 1, 25 dihydroxy vitamin D (1, 25-(OH) 2 D) respectively [12]. The active form of vitamin D is called calcitriol or 1, 25-dihydroxyvitamin D3. Serum 25(OH) D is used to reflect vitamin D status because it is the major circulating precursor of active vitamin D and has a half-life, ranging from two to three weeks. Interestingly, 1, 25-(OH) vitamin D has a short circulating half-life and is tightly under the influence of