Sedrani S H, Elidrissy A W, El Arabi K M
Am J Clin Nutr. 1983 Jul;38(1):129-32. doi: 10.1093/ajcn/38.1.129.
Serum levels of the circulating form of vitamin D3, 25-hydroxycholecalciferol [25-(OH)D3], were determined in 59 university students, 26 males and 33 females, aged 18 to 26 yr and in 24 elderly subjects, 13 males and 11 females, with a mean age of 62 +/- 13 yr. The level of 25-(OH)D3 was significantly lower in the elderly persons (p less than 0.001) than in young students of both sexes, and was significantly higher in females than in males. Serum levels of 1, 25- and 24, 25-dihydroxycholecalciferol were measured in adult males and found to be within the normal range. A group of elderly patients were exposed to natural uv light, and the circulating levels of 25-(OH)D3, serum phosphorus, and alkaline phosphatase were determined both before and 1 day after the last exposure. The exposure to natural uv light resulted in a 2 1/2-fold increase in the level of 25-(OH)D3 and a significant decrease in the activity of alkaline phosphatase, but no significant change in serum phosphorus concentrations was observed. It is concluded that the low vitamin D3 status in Saudis is mainly due to avoidance of sunlight exposure and other factors discussed below.
测定了59名年龄在18至26岁之间的大学生（26名男性和33名女性）以及24名老年受试者（13名男性和11名女性，平均年龄62±13岁）血清中循环形式的维生素D3即25-羟胆钙化醇[25-(OH)D3]的水平。老年人血清中25-(OH)D3的水平显著低于年轻的男女学生（p<0.001），且女性显著高于男性。对成年男性测定了血清1,25-二羟胆钙化醇和24,25-二羟胆钙化醇的水平，发现均在正常范围内。一组老年患者接受了自然紫外线照射，并在最后一次照射前和照射后1天测定了25-(OH)D3的循环水平、血清磷和碱性磷酸酶。自然紫外线照射使25-(OH)D3水平增加了2.5倍，碱性磷酸酶活性显著降低，但未观察到血清磷浓度有显著变化。得出结论，沙特人维生素D3水平低主要是由于避免阳光照射以及下文讨论的其他因素。
