Libon Florence, Courtois Justine, Le Goff Caroline, Lukas Pierre, Fabregat-Cabello Neus, Seidel Laurence, Cavalier Etienne, Nikkels Arjen F
Department of Dermatology, CHU of Sart Tilman, University of Liège, 4000, Liège, Belgium.
Department of Clinical Chemistry, CHU of Sart Tilman, University of Liège, Liège, Belgium.
Arch Osteoporos. 2017 Dec;12(1):66. doi: 10.1007/s11657-017-0361-0. Epub 2017 Jul 17.
A 50+ SPF sunscreen decreased significantly cutaneous vitamin D production following a single narrow-band (nb)UVB exposure, independently from the body surface area exposed. In contrast, the circulating 25(OH)D levels were only minimally affected. It is probable that another endogenous source of precursors is selected when skin-originated precursors are lacking.
Sunscreen use, highly advocated for preventing cutaneous carcinogenesis, is potentially leading to an aggravation of vitamin D deficiency with its consequences on bone health. The effect of sunscreens on circulating vitamin D levels remains debated. This study investigated the effect of sunscreen on cutaneous vitamin D production and circulating 25(OH)D levels, according to different body surface areas (BSA).
Vitamin D and 25(OH)D levels were measured in four groups exposed to a single nbUVB exposure on 9% (group I: head and hands), 23% (group II: head, hands and arms), 50% (group III: head, hands, arms and legs) and 96% (group IV: total body) of the body surface without and with a 50+ sun protection factor sunscreen.
Sunscreen use decreased by 83, 88.3, 75.7 and 92.5% the cutaneous vitamin D production in groups I to IV, respectively, but only by 13.2, 10.5, 7.7 and 10.4% the values of circulating 25(OH)D correspondingly.
Although a 50+ sunscreen decreases significantly cutaneous vitamin D production following a single nbUVB exposure, and independently from the BSA, the circulating 25(OH)D levels were only minimally affected. This could be explained by a switch to another endogenous source of precursors. Short-term sunscreen use probably does not affect circulating vitamin D levels and hence does not increase the risk for osteoporosis. The effect of long-term sunscreen use remains however to be determined.
一款防晒系数大于50的防晒霜在单次窄谱中波紫外线（nbUVB）照射后，会显著降低皮肤维生素D的生成，且与暴露的身体表面积无关。相比之下，循环中的25-羟维生素D[25(OH)D]水平仅受到极小影响。当缺乏皮肤来源的前体物质时，很可能会选择另一种内源性前体物质来源。
防晒对于预防皮肤癌的作用被大力提倡，但这可能会加重维生素D缺乏，并对骨骼健康产生影响。防晒霜对循环中维生素D水平的影响仍存在争议。本研究根据不同的身体表面积（BSA），调查了防晒霜对皮肤维生素D生成及循环中25(OH)D水平的影响。
对四组受试者进行单次nbUVB照射，分别暴露身体表面积的9%（I组：头部和手部）、23%（II组：头部、手部和手臂）、50%（III组：头部、手部、手臂和腿部）和96%（IV组：全身），且一组不使用防晒霜，其余三组使用防晒系数大于50的防晒霜，然后测量维生素D和25(OH)D水平。
使用防晒霜后，I至IV组皮肤维生素D的生成分别降低了83%、88.3%、75.7%和92.5%，但循环中25(OH)D的水平仅相应降低了13.2%、10.5%、7.7%和10.4%。
尽管一款防晒系数大于50的防晒霜在单次nbUVB照射后会显著降低皮肤维生素D的生成，且与身体表面积无关，但循环中25(OH)D水平仅受到极小影响。这可以通过转向另一种内源性前体物质来源来解释。短期使用防晒霜可能不会影响循环中维生素D的水平，因此不会增加骨质疏松的风险。然而，长期使用防晒霜的影响仍有待确定。
