Why the allergy epidemic did not already start 1935 in Germany

moblog – I have now spent another day at the Berlin Document Center browsing through hundreds of RKI pages – manuscripts, correspondence, bills and personal files. My goal was to find out why the allergy epidemic did not already start off 1935 in Germany when vitamin D synthesis was already possible on a large scale.
Indeed, I found evidence that at least 3 companies radiated at that time yeast derived ergosterin by UV quartz lamps – I.G. Farben, Nordmark-Werke and Deutsche Vitamin Gesellschaft. The number of companies in this field was probably limited by the American Steenbock patent. Quartz bulb power was difficult to control and even lost activity over time, a reason why some vitamin D preparations contained only low activities (R86-3588). A clinical trial in a child care unit in Hamburg (reported by a letter of the municipality of Hamburg 22.9.1941) showed that 46% of 200 children developed signs of rickets despite vitamin D supplements! So my earlier impression that vitamin D supplementation has been wide spread (and efficient) was certainly wrong.

I made even another discovery that may relate to the last liver cod oil post: The “Deutsche Vitamin Gesellschaft” added provitamin A to their vitamin D preparation which my have suppressed the immunological activity of vitamin D while preserving the antirachitic activity.