Do you know the Barker hypothesis? It says that early life events may induce later disease. A new study in the Eur J Clin Nutr now reports
Children whose mothers had a 25(OH)-vitamin D concentration in pregnancy >75 nmol/l had an increased risk of eczema on examination at 9 months (OR 3.26, 95% CI 1.15–9.29, P=0.025) and asthma at age 9 years (OR 5.40, 95% CI, 1.09–26.65, P=0.038) compared to children whose mothers had a concentration of <30 nmol/l.
These are quite remarkable results. I wonder only why two forthcoming studies click + click using food frequency questionnaires will describe only a reduction of respiratory infection rates (which is not too bad in the context of the hygiene hypothesis) with no effects on allergy.
Food intake measures are probably not good enough for internal dose estimates as main source of vitamin D production is sunlight, isn´t it?
Addendum
12 March 2007 – the long awaited AJCN paper is now out. I have already feared that stratification by FFQ is only partially relevant. Indeed, the authors could have used also college graduate level which increased with intake catgeories 1-2-3-4 from 53-74-80-82% with all the problems by SES dependency (and not corrected for in model 2+3 in table 2 or model A…D in table 3). The discussion seems to be also far away from being an objective report on the immunology of vitamin D actions…