A caveat. If you take vitamin D you need to take magnesium because magnesium is used in the manufacturing of the hormone vitamin D is changed into called calcitrol. Occasionally a person will say, I do not feel well taking vitamin D. Most likely this is a result of dropping levels of magnesium. Magnesium oxide is the poorest of all the magnesium supplements and considered by most to be not worth taking. Any of the others are better.
All this is the price you pay for living away from the equator, eating fast foods, getting old, wearing clothes and not drinking well water. Welcome to the diseases of civilization!
So now for the controversy. Copy and paste.....