Matsuoka L Y, Wortsman J, Hanifan N, Holick M F
Department of Dermatology, Jefferson Medical College, Philadelphia, PA 19107.
Arch Dermatol. 1988 Dec;124(12):1802-4.
Sunscreens block the absorption of the sunlight spectrum responsible for the cutaneous synthesis of vitamin D (ultraviolet B). The present study was prompted by our observation of suppression of cutaneous vitamin D formation by a single application of sunscreening agents. We measured the index of vitamin D body store, serum 25-hydroxyvitamin D (25-OH-D) level, in 20 long-term users of p-aminobenzoic acid (PABA) and in 20 controls matched by age and exposure to sunlight. Serum 25-OH-D levels were significantly lower among long-term PABA users than among normal controls: 40.2 +/- 3.2 vs 91.3 +/- 6.2 nmol/L. Furthermore, vitamin D deficiency, ie, 25-OH-D levels below 20.0 nmol/L, was seen in two PABA users and in none of the controls. This preliminary study suggests that long-term use of PABA may be associated with low body stores of vitamin D in some persons.
防晒霜会阻碍皮肤合成维生素D（紫外线B）所需的阳光光谱的吸收。我们观察到单次涂抹防晒剂会抑制皮肤维生素D的形成，由此开展了本研究。我们测量了20名长期使用对氨基苯甲酸（PABA）的使用者以及20名年龄和阳光照射情况相匹配的对照者的维生素D体内储备指标，即血清25-羟基维生素D（25-OH-D）水平。长期使用PABA的使用者的血清25-OH-D水平显著低于正常对照组：分别为40.2±3.2和91.3±6.2nmol/L。此外，两名PABA使用者出现了维生素D缺乏，即25-OH-D水平低于20.0nmol/L，而对照组中无人出现这种情况。这项初步研究表明，长期使用PABA可能会使某些人的维生素D体内储备较低。
