Normal vitamin D levels can be maintained despite rigorous photoprotection: six years' experience with xeroderma pigmentosum

J Am Acad Dermatol. 1997 Dec;37(6):942-7. doi: 10.1016/s0190-9622(97)70069-0.

Abstract

Background: Although sun protection is advocated for skin cancer prevention, sunlight is also important in generation of vitamin D in the skin. There is concern that sun protection may result in an abnormally low level of vitamin D.

Objective: To assess the risk of vitamin D deficiency in a sunlight-deprived population, we studied eight ambulatory patients with xeroderma pigmentosum (XP) who practiced intensive sun protection during a chemoprevention study of oral isotretinoin.

Methods: We surveyed the patients to determine the extent of sun protection and vitamin D intake and measured the serum levels of two vitamin D metabolites (25-hydroxyvitamin D [25-OHD] and 1,25-dihydroxyvitamin D [1,25-(OH)2D]), calcium, and parathyroid hormone during 6 years.

Results: The patients all wore protective clothing and sunscreens when outdoors. Estimated mean vitamin D intake was normal. The mean values of serum 25-OHD were low normal, but 1,25-(OH)2D, calcium, ionized calcium and parathyroid hormone levels were normal. Lack of seasonal variation in serum 25-OHD indicated rigorous photoprotection.

Conclusion: Despite rigorous sun protection normal vitamin D levels can be maintained in ambulatory patients with XP.

MeSH terms

  • Administration, Oral
  • Adolescent
  • Adult
  • Ambulatory Care
  • Calcium / blood
  • Chemoprevention
  • Dihydroxycholecalciferols / blood
  • Female
  • Follow-Up Studies
  • Humans
  • Isotretinoin / administration & dosage
  • Isotretinoin / therapeutic use
  • Keratolytic Agents / administration & dosage
  • Keratolytic Agents / therapeutic use
  • Male
  • Middle Aged
  • Parathyroid Hormone / blood
  • Protective Clothing
  • Risk Factors
  • Seasons
  • Skin / metabolism
  • Skin / radiation effects
  • Sunlight
  • Sunscreening Agents / administration & dosage
  • Sunscreening Agents / therapeutic use*
  • Vitamin D / administration & dosage
  • Vitamin D / analogs & derivatives
  • Vitamin D / biosynthesis
  • Vitamin D / blood*
  • Vitamin D / radiation effects
  • Vitamin D Deficiency / etiology
  • Xeroderma Pigmentosum / blood
  • Xeroderma Pigmentosum / prevention & control*

Substances

  • Dihydroxycholecalciferols
  • Keratolytic Agents
  • Parathyroid Hormone
  • Sunscreening Agents
  • Vitamin D
  • 1,25-dihydroxyvitamin D
  • Isotretinoin
  • Calcium