My 25(oh)d is 41ng/ml, how much vit d3 should i take every day & for how long(i have osteoporosis & thus result after 45 days taking 5000 iu daily.

? ~50,000 IU/wk: I usually wait ~3 months before rechecking d3 concentration, it takes time to change. With osteoporosis, d3 conc. In at least the 70-80 upper normal, range probably desirable (assuming no hx ca renal stones). Also ↑ foods high in ca+2 (e.g. Dairy, cheese), possibly citracal for additional ca+2 may help. Depending on severity, consider recheck lunar DEXA at 1 year intervals. Many otc d3 ↓ efficacy.