Blood work says vitamin d levels are (44nmol/l)... 17.6ng/ml. take 2000iu vitamin d3 daily. insight? recommendations? live in cold climate/lack of sun

In the darkness: B"sd Despite endless studies the "correct" recommended level of vitamin D remains quite arbitrary - usually given as 30 but as low as 15 may be fine. Some recent studies also suggest higher levels may even be harmful. In some cases I check the calcium and parathyroid hormone levels (PTH) as elevated levels usualy reflect Vit D deficiency. Reasonable to me to increase vit D3 to 3000 u/day.