I looked into d3, and found this :
http://www.independent.co.uk/life-s...hat-could-be-bad-for-your-health-2154057.html
Extract : "This review found that information about the health benefits [of vitamin D] beyond bone health were from studies that provided often mixed and inconclusive results and could not be considered reliable," the committee said.
They recommend people need 600 international units a day (800 a day over age 70) and warn that doses above 4,000 units a day may be harmful.
Vitamin D supplements containing 5,000 units per pill are widely available in the US, and can also be bought in the UK.
"Very high levels of vitamin D (above 10,000 IUs per day) are known to cause kidney and tissue damage. Some preliminary studies offer tentative signals about adverse health effects [at lower levels]", they add.