The situation is far worse that detailed above.
The problem arises because the level defining deficiency is set only at the level that prevents rickets.75nmol/l.
If you want to absorb maximum amounts of calcium from your diet then 80nmol/l is the minimum. If you want that calcium to stay put in your bones, so you have maximum Bone Mineral Density most people require 110nmol/l. But it doesn't end there.
Your body works best when it has more vitamin D coming in than it uses daily. When there is stored Vitamin D3 it is better able to deal with infection so at levels ABOVE 137.5nmol/l we find least incidence of most chronic diseases. If you think it's a smart move to have your baby born not only with strong bones but also with access to Vitamin D3 naturally present in mothers breast milk then a level around 150nmol/l is ideal. If you have a cancer diagnosis and want to be better able to reduce the proliferation of cancer cells than a high and stable 25(OH)D3 level is required.
This paper Circulating 25-Hydroxyvitamin D Levels in Fully Breastfed Infants on Oral Vitamin D Supplementation
is free online and shows 6400iu/daily/D3 is required to optimize vitamin D3 in breast milk.
While food fortification may help it would be better if EFFECTIVE amounts where provided in prenatal vitamins.
TedHutchinson - Louth / UK,/ retired
Everyone should know about the connection between vitamin D deficiency and cancer, especially breast and colon cancer. You can see all the data at www.vitaminD3world.com The site also has links to a very neat micro tablet version of vitamin D3
toby lee - Dover DE
A while ago I came across this very readable 47-page report published by the Health Research Forum in 2004: 'Sunlight Robbery: Health benefits of sunlight are denied by current public health policy in the UK'. It is available online at http://www.healthresearchforum.org.uk/reports/sunlightrobbery.pdf
Loraine Wojciechowicz - Intute, University of Nottingham