Efficacy of the Dose Regimen of Oral Vitamin D 50,000 IU in the Treatment of Vitamin D Deficiency

Inclusion criteria: * Subject is willing and able to give voluntary informed consent for participation in the study. * Ethnic group (Caucasian). * Healthy males or females aged between 18 and 49 years old. * Normal weight (BMI 18.5-25kg/m2). * Physical examination being assessed and accepted by the attending physician. * Systolic blood pressure within the normal range (90-140) mmHg. * Diastolic blood pressure within the normal range (60-90) mmHg. * Heart rate within the normal range (60-100 beats/min). * Oral body temperature within the normal range (35.9 - 37.6 Cº). * Diagnosed with vitamin D deficiency with 25-OH Vitamin D level \< 20ng/ml. * All laboratory tests which including : Urine analysis, Hematology (Hb, Packed Cell Volume, Red Blood Cell, Mean Corpuscular Hemoglobin , Mean Corpuscular Hemoglobin Concentration , Mea Corpuscular Volume, Leukocytes, Lymphocytes, Eosinophils, Basophils, Monocytes, Neutrophils, Platelet count), Kidney function tests, Liver function test, Virology, Clinical chemistry, Ca, Mg, PO4, PTH , Alkaline Phosphatase and pregnancy test for married females ,results within the normal reference range. * Able and willing to comply with all study requirements. Exclusion Criteria The subject may not enter the study if ANY of the following apply: * Female subjects who is pregnant, lactating or planning pregnancy during the course of the study. * Ethnic group non Caucasian. * Males and Females aged \<18 or \>49 years old. * Underweight, overweight and obese Females and males * Males and Females diagnosed with diabetes, hypothyroidism, hyperthyroidism, liver disease, renal dysfunction, cardiovascular diseases including hypertension, androgen-secreting tumor, Cushing syndrome, congenital adrenal hyperplasia, hyperprolactinemia, and/or virilism. * Known history or presence of food allergies or intolerance (e.g dairy products or gluten containing food), or any known condition that could interfere with the absorption, distribution, metabolism or execration of drugs. * History of drug or alcohol abuse, smoking of 10 cigarettes or more (or equivalent) per day. * Subjects who took medications known to affect metabolic parameters, such as metformin and corticosteroid drugs, vitamin D and calcium. * Participation in another clinical or bioequivalence study within 90 days prior to the start of this study period. * Subjects with abnormal ECG. * Subjects with any abnormal laboratory results except 25 OH-Cholecalciferol level.