Maccabi Health Services has begun to encourage its general practitioners and family physicians to send all patients for vitamin D testing, after finding that 36 percent of blood samples tested in its labs are deficient in the essential vitamin (having less than 20 nanograms per milliliter, while 32 mgs. is regarded as desirable). Maccabi director-general Dr. Ehud Kokia decided to take action after receiving a query from The Jerusalem Post about vitamin D deficiency. Until now, no screening was carried out, because of the lack of an international standard, he said. The second largest health fund took the initiative without the Health Ministry giving any instructions encouraging vitamin D screening of the population, requiring the dairy industry to fortify milk products with the inexpensive vitamin or requiring that all standard health fund lab tests include testing for the vitamin. Children and adults found to have vitamin D deficiencies should speak to their doctors, who are likely to prescribe vitamin D drops taken in water or juice on a daily basis. It has long been thought that those living in sunny Israel have low vitamin D deficiency rates because exposure to the sun's ultraviolet rays produces the vitamin in the skin. But Maccabi director-general Kokia told the Post on Tuesday that this can no longer be taken for granted because of changed lifestyles. Not only are people spending less time outdoors, they also cover themselves up to minimize the skin cancer danger and ageing of the skin from sun exposure, he said. While there is less vitamin D deficiency in the summer, even during the hotter months, many Israelis suffer from a lack of the vitamin, Kokia said. He added that Maccabi had invited experts in the field, including leading endocrinologists inside and outside the health fund, to meet and discuss the problem. Diabetics and the overweight are more likely to be deficient in vitamin D than others, but religious people who cover themselves up for reasons of modesty are also at high risk, as are haredi children and teenagers who spend little time outdoors.