It is some time since I visited the site and I notice there are comments appearing about unsafe upper levels of Vitamin D3. About a year ago my last blood test was 165.9 nmol/l and my wife was 128.1 nmol/l. This is with 5000 iu D3 daily supplementation and not too much sunlight because we are in the far north.
We are both in our late 60s. Are these levels too high and potentially detrimental? What optimum blood level should we be aiming for?