title: Chronic sunscreen use decreases circulating concentrations of 25-hydroxyvitamin D. A preliminary study.
abstract: 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.
authors.affiliation: Department of Dermatology, Jefferson Medical College, Philadelphia, PA 19107.
authors.forename: L Y
authors.initials: LY
authors.lastname: Matsuoka
authors.forename: J
authors.initials: J
authors.lastname: Wortsman
authors.forename: N
authors.initials: N
authors.lastname: Hanifan
authors.forename: M F
authors.initials: MF
authors.lastname: Holick
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002112:Calcifediol / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012621:Seasons; D012878:Skin Neoplasms / Q000517:prevention & control; D013473:Sunscreening Agents / Q000009:adverse effects*; D013997:Time Factors; D014808:Vitamin D Deficiency / Q000139:chemically induced
chemical_list: D013473:Sunscreening Agents; D002112:Calcifediol