Department of Dermatology and Venereology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Department of Community Medicine, Government Medical College, Kannauj, Uttar Pradesh, India.
Indian J Dermatol Venereol Leprol. 2019 May-Jun;85(3):282-286. doi: 10.4103/ijdvl.IJDVL_575_17.
Use of sunscreens on the face is becoming popular, and patients with melasma are prescribed sunscreen for use on the face. Results of a few Western studies on the effect of sunscreen use on serum vitamin D concentration are not applicable to Indian conditions.
To examine the effect of use of a high sun protection factor (SPF 50+, PA++++) sunscreen on face in patients with melasma on serum concentration of 25-hydroxyvitamin D.
Forty-five Indian patients (Fitzpatrick skin types III and IV) with melasma were advised to use a sunscreen with SPF 50 + for 3 months, 43 (33 female, 10 male; age 32.9 ± 8 years) completed the study. Patients staying outdoor for <4 hours applied sunscreen once daily after bath. Patients staying outdoors for >4 hours reapplied sunscreen 4 hours after first application. Patients were provided a container to measure the amount of sunscreen for use, which was approximately equal to recommended thickness. Compliance was tested by weighing the used tubes and tubes in use during monthly visits. Serum concentration of 25-hydroxyvitamin D was tested before and after the study period.
Amount of sunscreen advised (100.5 ± 29.2 ml) and the actual amount used (96.6 ± 27.9 ml) were similar (P = 0.53, t-test). The difference between serum concentrations of 25-hydroxyvitamin D at the baseline (19.20 ± 9.06 ng/ml) and at 3 months (18.91 ± 8.39 ng/ml) was not significant (P = 0.87, paired t-test, 95% confidence interval of difference -3.33 to 3.92). No correlation was found between the amount of sunscreen used and the percentage change in serum 25-hydroxyvitamin D concentration at 3 months (rho = 0.099, P = 0.528, Spearman's rank correlation).
Longer duration of application and a larger sample size may detect minor differences in vitamin D concentration.
Using a high SPF sunscreen on the face, along with physical photoprotection advice, in patients with melasma for 3 months does not influence serum 25-hydroxyvitamin D concentration in Indian conditions.
防晒霜在面部的使用越来越普及，黄褐斑患者也被开出处方使用防晒霜。少数几项关于防晒霜使用对面部血清维生素 D 浓度影响的西方研究结果并不适用于印度情况。
研究使用高防晒因子（SPF50+，PA+++）防晒霜对面部黄褐斑患者血清 25-羟维生素 D 浓度的影响。
建议 45 名印度黄褐斑患者（Fitzpatrick 皮肤类型 III 和 IV）使用 SPF50+防晒霜，共 3 个月，其中 43 名（33 名女性，10 名男性；年龄 32.9±8 岁）完成了研究。户外活动时间<4 小时的患者每天沐浴后涂抹一次防晒霜，户外活动时间>4 小时的患者第一次涂抹 4 小时后再次涂抹防晒霜。为患者提供一个容器来测量防晒霜的使用量，大约等于推荐的厚度。每月就诊时通过称重使用过的管和正在使用的管来测试依从性。在研究前后测试血清 25-羟维生素 D 浓度。
建议的防晒霜用量（100.5±29.2ml）和实际使用量（96.6±27.9ml）相似（P=0.53，t 检验）。血清 25-羟维生素 D 浓度在基线（19.20±9.06ng/ml）和 3 个月（18.91±8.39ng/ml）之间的差异无统计学意义（P=0.87，配对 t 检验，95%置信区间差异为-3.33 至 3.92）。使用的防晒霜量与 3 个月时血清 25-羟维生素 D 浓度变化百分比之间无相关性（rho=0.099，P=0.528，Spearman 等级相关）。
更长的应用时间和更大的样本量可能会检测到维生素 D 浓度的微小差异。
在印度条件下，黄褐斑患者面部使用高 SPF 防晒霜，并结合物理防晒建议，连续使用 3 个月不会影响血清 25-羟维生素 D 浓度。
