School of Molecular Bioscience, University of Sydney, NSW, 2006, Australia; Nutrition Research Australia, Sydney NSW, 2000, Australia.
Faculty of Health Sciences, University of Sydney, NSW, 2006, Australia; Physiology, School of Medical Sciences, University of Sydney, NSW, 2006, Australia.
J Steroid Biochem Mol Biol. 2019 May;189:127-134. doi: 10.1016/j.jsbmb.2019.02.017. Epub 2019 Mar 1.
Low vitamin D status, measured as 25-hydroxyvitamin D (25OHD), has been linked to increased risk of osteoporosis and other disorders. Due to the indoor nature of office work, there may be an increased risk of 25OHD deficiency in this group. The aim of the current study was to evaluate seasonal variations of 25OHD in a population of healthy office workers, and to assess the effect of sun exposure behaviour, skin pigmentation, physical activity (PA) and dietary intake on serum 25OHD concentrations. We assessed the vitamin D status of healthy office workers in Sydney, Australia, at the end of summer (n = 103) and then at the end of winter (n = 71). Data on anthropometry, PA, dietary intake, sun exposure and skin phototype were collected along with blood samples. Serum 25OHD was measured by radioimmunoassay. Mean 25OHD concentration in late summer was 68 ± 27 nmol/L (range: 24-160 nmol/L), and in late winter was 59 ± 32 nmol/L (range: 15-174 nmol/L). 25OHD deficiency (<50 nmol/L) was observed in 29% and 42% of participants at end-summer and end-winter, respectively. Almost 10% of individuals were extremely deficient (<25 nmol/L) at end-winter, particularly those with dark skin (phototypes 5 and 6). Independent predictors of end-summer 25OHD were skin phototype (p < 0.02), summer sun exposure (p < 0.001) and skin area exposed (p = 0.005). The strongest predictor of end-winter 25OHD was end-summer 25OHD concentration (p < 0.001). If this was excluded from the model, the independent predictors of end-winter 25OHD were skin phototype (p < 0.01), sun exposure in winter (p = 0.01) and oily fish consumption (p < 0.05). Sunscreen use was significantly associated with higher vitamin D status (p < 0.05) as those who used sunscreen were also more likely to spend time outdoors. We conclude that sun exposure is beneficial for vitamin D status even with sunscreen use. Vitamin D supplements should be targeted to individuals who are darker skinned or unable to obtain adequate sun exposure, particularly during the winter months.
维生素 D 状态低下，即 25-羟维生素 D（25OHD）水平较低，与骨质疏松症和其他疾病的风险增加有关。由于办公室工作的性质主要在室内，因此该人群可能存在 25OHD 缺乏的风险增加。本研究的目的是评估健康的办公室工作人员群体中 25OHD 的季节性变化，并评估阳光暴露行为、皮肤色素沉着、身体活动（PA）和饮食摄入对血清 25OHD 浓度的影响。我们在澳大利亚悉尼评估了健康上班族在夏末（n=103）和冬末（n=71）的维生素 D 状态。收集了人体测量学、PA、饮食摄入、阳光暴露和皮肤光型的数据以及血液样本。血清 25OHD 通过放射免疫分析法进行测量。夏末时平均 25OHD 浓度为 68±27nmol/L（范围：24-160nmol/L），而冬末时为 59±32nmol/L（范围：15-174nmol/L）。在夏末和冬末，分别有 29%和 42%的参与者存在 25OHD 缺乏（<50nmol/L）。在冬末，几乎有 10%的个体严重缺乏（<25nmol/L），尤其是皮肤较深（5 型和 6 型）的个体。夏末 25OHD 的独立预测因素是皮肤光型（p<0.02）、夏季阳光暴露（p<0.001）和暴露皮肤面积（p=0.005）。冬末 25OHD 的最强预测因素是夏末 25OHD 浓度（p<0.001）。如果从模型中排除这一因素，冬末 25OHD 的独立预测因素是皮肤光型（p<0.01）、冬季阳光暴露（p=0.01）和食用油性鱼类（p<0.05）。防晒霜的使用与更高的维生素 D 状态显著相关（p<0.05），因为使用防晒霜的人更有可能在户外活动。我们得出的结论是，即使使用防晒霜，阳光暴露也有利于维生素 D 状态。维生素 D 补充剂应针对皮肤较深或无法获得足够阳光暴露的个体，尤其是在冬季。
