The answer to the question as to the adult's need for vitamin D clearly is, "Yes, but not so much as the growing organism." Short laboratory experiments on normal men and women have not as yet shown any effect from adding or withdrawing vitamin D, but in certain abnormal conditions its influence has been demonstrated, especially in a serious disease of the bones, osteomalacia. The latter disturbance, in one of its manifestations at least, appears to be a deficiency disease traceable to lack of vitamin D or light.
EXPERIMENTS ON NORMAL MEN AND WOMEN
The three following experiments, performed on normal men and women, were planned so that an influence from giving vitamin D might have been expected, but all of them showed only negative results.
—Some healthy young men in England were found to show a certain amount of seasonal variation in the inorganic phosphorus of the