After 6 months, mean serum 25(OH)D increased to 53 nmol/l with 800 IU/day, to 50.5 nmol/l with 100,000 IU/3 months, and to 29.1 nmol/l with advised sunlight exposure (supplementation vs sunshine p < 0.001).
vitamin D 800IU/day or 100,000IU/3months
sunlight exposure
demographic and prognostic variables, and baseline values of outcome measurements