导读：当看到这个标题，你可能不可思议，茫然不知所措。其实文章真正的意义在于要说明健康女性维生素D缺乏与炎症增加有密切关系。这里所指的炎症不是细菌、病毒等病原微生物感染引起的炎症，而是特指非感染性炎症。它在发病时也有“红、肿、热、痛”炎症样表现，可能与自身免疫异常有关。反映此身体存在炎症与否，关键看血液中肿瘤坏死因子（TNF）-α和C-反应蛋白炎症等标识物的变化。已知在炎症活动时，TNF-α浓度就升高。由于维生素D能抑制TNF-α生成，以此发挥治疗炎症性疾病的作用。一旦维生素D缺乏，体内的炎症就会“疯”起来！

2009年4月14日，《科学日报》报道近期《内科学文献》的一项研究：75%的美国人难以通过日常饮食获取足够的维生素D。研究发现，维生素D缺乏可能对人体免疫功能和心血管健康状况产生不利的影响，并有增加癌症的风险。日前，美国密苏里州大学营养学科的研究者发现，在健康的女性中，维生素D缺乏与炎症密切相关，系由于免疫系统负面反应所导致的。

研究发现，缺乏维生素D的女性，炎症标识物--血清TNF-α浓度升高。这是首次发现，维生素D水平与TNF-α浓度在健康人群中存在负相关。这或许可以说明维生素在预防和治疗炎症疾病中的作用，包括心脏疾病、多发性硬化和风湿性关节炎。

“研究结果表明，即使健康人群，维生素D水平低对炎症和免疫系统有负面影响。”美国密苏里州大学人类健康科学的Catherine Peterson助理教授表示，“正常情况下，肥胖者或有慢性疾病的人存在炎症；病人的维生素D水平略有下降就会使症状加剧。”

该项研究结果说明，需要对维生素D的膳食参考摄入量（DRI）重新进行生物学方面的研究。当前，美国人维生素D的 DRI为：50岁及以下的人群200IU/日，50-70岁人群400IU/日，70岁以上的老人为600IU/日。这一标准是在1997年建立的，目前正在根据新的研究进行修订，Peterson认为这个DRI标准应当增加。     

“这次研究所得出的足够维生素D水平是与最近建议增加DRI标准的研究相一致的。”Peterson说。“要改善维生素D水平，达到有益健康状态，大多数人每天维生素D的补充量最少应该在1000IU。太阳光是可利用的免费维生素D资源。对大多数人来说，皮肤的25%每周3天暴露在太阳底下10分钟就足以维持足够的维生素D水平，但对深色皮肤的人来说需要暴露更长时间。只有很少的食物含有天然维生素D，例如多脂肪的鱼。维生素D的其它来源是补充剂和强化维生素D的食物，如牛奶和桔子汁。

Vitamin D Deficiency Related To Increased Inflammation In Healthy Women

ScienceDaily (Apr. 14, 2009) — According to a recent study in the Archives of Internal Medicine, 75 percent of Americans do not get enough Vitamin D. Researchers have found that the deficiency may negatively impact immune function and cardiovascular health and increase cancer risk. Now, a University of Missouri nutritional sciences researcher has found that vitamin D deficiency is associated with inflammation, a negative response of the immune system, in healthy women.

 Increased concentrations of serum TNF-α, an inflammatory marker, were found in women who had insufficient vitamin D levels. This study is the first to find an inverse relationship between vitamin D levels and concentrations of TNF-α in a healthy, non-diseased population. This may explain the vitamin's role in the prevention and treatment of inflammatory diseases, including heart disease, multiple sclerosis and rheumatoid arthritis.

"The findings reveal that low vitamin D levels negatively impact inflammation and immune response, even in healthy women," said Catherine Peterson, assistant professor in the MU College of Human Environmental Sciences. "Increased inflammation normally is found in people with obesity or chronic diseases; a small decrease in vitamin D levels may aggravate symptoms in people who are sick."

The results support the need to re-examine the biological basis for determining the dietary reference intake (DRI) of vitamin D, Peterson said. The Institute of Medicine's DRI for vitamin D is 200 IU for people age 50 and younger and 400 IU for people 50 to 70 years old. The guidelines, created in 1997, are being revised to reflect new research, and Peterson is confident the DRI will be increased.

"Adequate vitamin D levels identified in this study are consistent with recent research that suggests the DRI should be increased," Peterson said. "To improve vitamin D status and achieve its related health benefits, most people should get at least 1000 IU of vitamin D per day. Sunlight is a readily-available, free source of vitamin D. Exposing 25 percent of the skin's surface area to 10 minutes of sunlight three days per week will maintain adequate levels in the majority of people; however, people with darkly-pigmented skin need more. Only a few foods contain vitamin D naturally, such as fatty fish; other sources are dietary supplements and vitamin-D-fortified foods, including milk and orange juice."

In future studies, Peterson will determine the effectiveness of Vitamin D in reducing disease symptoms and reducing blood glucose levels in diabetics. The study, "Serum tumor necrosis factor-alpha concentrations are negatively correlated with serum 25(OH) D concentrations in healthy women," was published in the July, 2008 issue of the Journal of Inflammation.