Hypothyroidism is a pathophysiological phase in which insufficient hormones are produced leading to an imbalance in basal metabolic rate and inefficiency physiological role of body systems. Vitamin D affects thyrocytes by decreasing TSH stimulated iodide uptake and cellular development. In hypothyroidism, hypovitaminosis D are due to malabsorption from the intestine and the other mechanism is inactivation of vitamin D. Thyroid hormones induce erythropoietin gene expression causing increase secretion of erythropoietin. Iron deficiency decreases activity of thyroid peroxidase enzyme. Hypothyroidism can cause microcytic anemia due to malabsorption of iron and menorrhagia. Hypothyroidism is a common but under-recognized and under-diagnosed condition in the Persian Gulf countries. Moreover, the effect of hypothyroidism on vitamin D and iron levels were inadequately evaluated. This is important to identify bi-deficiency so that, doctors can treat them earlier and can reduce the deficiency-related complications. There are plenty scopes for study on bi-deficiencies status of hypothyroid population.