Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Curr Opin Endocrinol Diabetes Obes. 2016 Dec;23(6):440-444. doi: 10.1097/MED.0000000000000288.
The clinical benefits of vitamin D therapy have received substantial attention over the past decade. Recently, several trials looked to clarify the optimal vitamin D dose or serum level needed to promote human health. The purpose of this review is to highlight selected studies published since January 2015.
Several recent trials challenge whether serum vitamin D levels at least 30 ng/ml promote human health. In postmenopausal women with 25-hydroxyvitamin D [25(OH)D] levels 21 ± 3 ng/ml, high-dose vitamin D for 1 year increased calcium absorption by 1%, without changes in bone mineral density, physical function, or falls when compared with low-dose vitamin D and placebo. High-dose vitamin D increased risk of falling in 200 adults 78 ± 5 years old with baseline 25(OH)D levels of ∼19 ± 9 ng/ml. High-dose vitamin D in adults increased the number and duration of upper respiratory tract infections compared with placebo. Asthma patients achieving 25(OH)D levels more than 30 ng/ml during a trial experienced more respiratory infections than those not achieving such levels.
Recent studies are congruent with the Institute of Medicine's conclusion that humans are vitamin D replete when their serum 25(OH)D levels are at least 20 ng/ml. Higher levels seem to promote falls and respiratory infections.
在过去的十年中，维生素 D 治疗的临床益处受到了广泛关注。最近，几项试验试图阐明促进人体健康所需的最佳维生素 D 剂量或血清水平。本综述的目的是重点介绍自 2015 年 1 月以来发表的一些选定研究。
几项最近的试验对血清维生素 D 水平至少 30ng/ml 是否促进人体健康提出了质疑。在 25-羟维生素 D [25(OH)D]水平为 21±3ng/ml 的绝经后妇女中，与低剂量维生素 D 和安慰剂相比，高剂量维生素 D 治疗 1 年可使钙吸收率增加 1%，而骨密度、身体功能或跌倒率无变化。在基线 25(OH)D 水平约为 19±9ng/ml 的 200 名 78±5 岁成年人中，高剂量维生素 D 增加了跌倒的风险。与安慰剂相比，高剂量维生素 D 增加了成年人上呼吸道感染的次数和持续时间。在一项试验中，25(OH)D 水平超过 30ng/ml 的哮喘患者比未达到该水平的患者经历更多的呼吸道感染。
最近的研究与医学研究所的结论一致，即当人体血清 25(OH)D 水平至少为 20ng/ml 时，人体就会有足够的维生素 D。更高的水平似乎会增加跌倒和呼吸道感染的风险。
