inclusion criteria: age ≥30 years old male and female jordanian asu students and employees who live in amman. informed written consent from the participant prior to the start of the study. a serum 25(oh)d concentration less than 30 ng/ml.

inclusion criteria: age ≥30 years old male and female jordanian asu students and employees who live in amman. informed written consent from the participant prior to the start of the study. a serum 25(oh)d concentration less than 30 ng/ml.