Available data supporting a target serum level of at least 75 nmol/l 25-hydroxyvitamin D (25-OHD) include studies on bone mineral density (bmd), fracture prevention, lower extremity function, and cancer prevention. Given the high cost and disability from falls, fractures, and cancer treatment a shared threshold for 25-OHD has significant public health implications, especially so, if a large part of the population is below this threshold. This article summarizes available evidence supporting the 75 nmol/l threshold, reviews adherence to Vitamin D treatment in fracture trials in regard to achieved anti-fracture efficacy, and finally discusses current recommendations for Vitamin D intake.