Wu Shou-En, Chen Wei-Liang
Department of Dermatology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei City, Taiwan.
Division of Family Medicine, Department of Family and Community Medicine, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei City, Taiwan.
Front Nutr. 2022 Mar 8;9:832659. doi: 10.3389/fnut.2022.832659. eCollection 2022.
Vitamin (Vit) D plays a vital role in human health, and the prevalence of Vit D deficiency worldwide has been a rising concern. This study investigates the serum 25-hydroxy-Vit D [25(OH)D] status in healthy US civilians and identifies how the two main sources, sun exposure and dietary Vit D intake, determine the final 25(OH)D levels in individuals.
A total of 2,360 of participants from The National Health and Nutrition Examination Survey (NHANES) 2009-2014 were analyzed. We divided the levels of sun exposure and dietary Vit D intake of all subjects into 10 strata and gave a score ranging from 1 to 10 points, respectively. Scores 1-5 in sun exposure and dietary intake were considered as relatively low exposure groups, whereas scores 6-10 were considered as relatively high exposure groups. Serum Vit D inadequacy was defined as <50 nmol/L. Linear and logistic regression analyses were used to examine the associations between sources of Vit D and serum 25(OH)D levels.
In relatively low Vit D intake groups (Vit D intake score 1-5), relatively high sun exposure (sun exposure score >5) resulted in higher serum 25(OH)D levels (average 57 nmol/L) compared with relatively low sun exposure (sun exposure score <5) (average 50 nmol/L), whereas this difference became negligible in high intake groups (Vit D intake score 6-10). Moreover, the greatest slope occurred in the low Vit D intake curve (decile 3 of Vit D intake), which shows increased sun exposure time causing the greatest degree of change in serum 25(OH)D level in this group.
Sun exposure can significantly make up for deficiencies in subjects who consume insufficient dietary Vit D. Compared with the extra cost and time for building habits of Vit D supplementation, moderate sun exposure appears to be a simple and costless means for the public to start in daily practice.
维生素D在人类健康中起着至关重要的作用，全球维生素D缺乏症的患病率日益受到关注。本研究调查了美国健康平民的血清25-羟基维生素D[25(OH)D]水平，并确定了两个主要来源，即阳光照射和饮食中维生素D的摄入量，如何决定个体最终的25(OH)D水平。
对2009 - 2014年美国国家健康与营养检查调查（NHANES）中的2360名参与者进行了分析。我们将所有受试者的阳光照射水平和饮食中维生素D的摄入量分为10个层次，并分别给出1至10分的评分。阳光照射和饮食摄入评分1 - 5分被视为相对低暴露组，而评分6 - 10分被视为相对高暴露组。血清维生素D不足定义为<50 nmol/L。采用线性和逻辑回归分析来检验维生素D来源与血清25(OH)D水平之间的关联。
在维生素D摄入量相对较低的组（维生素D摄入评分为1 - 5分）中，与阳光照射相对较少（阳光照射评分为<5分）（平均50 nmol/L）相比，阳光照射相对较多（阳光照射评分为>5分）导致血清25(OH)D水平更高（平均57 nmol/L），而在高摄入量组（维生素D摄入评分为6 - 10分）中这种差异变得微不足道。此外，最大斜率出现在维生素D摄入量低的曲线（维生素D摄入量的十分位数3）中，这表明在该组中增加阳光照射时间会导致血清25(OH)D水平变化程度最大。
阳光照射可以显著弥补饮食中维生素D摄入不足的受试者的不足。与养成补充维生素D习惯所需的额外成本和时间相比，适度的阳光照射似乎是公众在日常实践中可以采用的一种简单且无成本的方法。
