25-Hydroxyvitamin D serum levels in rheumatic female patients in southeast Spain: The paradigm of daily optimal sunshine levels and inadequate vitamin D status.

BACKGROUND: Almeria is a region in southeast Spain with optimal sunlight levels, along with low pluvial and pollution rates. If exposure to sunlight is sufficient to maintain adequate levels of vitamin D (25OHD), this population should display high serum levels.

OBJECTIVES: To describe 25OHD serum status in women from Almeria and evaluate the impact of long sunlight exposure along the seasons on 25OHD.

METHODS: Cross-sectional study, performed in women consecutively recruited from an outpatient rheumatology clinic. Serum levels of 25OHD were assessed in all patients and evaluated according to age (<48 yrs, 48-53 yrs, 54-60 yrs and >60 yrs), season, and presence or absence of menopause. Clinical and laboratory variables that could affect status of vitamin D were also considered.

RESULTS: The sample included 319 Caucasian female patients. Mean 25OHD were 30.2ng/ml with 195 (61.1%) exhibiting 25OHD inadequate serum levels. Season had a significant effect on 25OHD levels, with autumn being the season in which 25OHD serum levels remained well above 30ng/ml in all age bands, and winter the season with more levels of insufficiency. Menopause did not modify 25OH serum levels. Women whose age was below 48 and over 60 had inadequate levels of 25OHD during summer.

CONCLUSIONS: Optimal levels of sunlight could not overcome the problem of inadequate 25OHD serum levels, particularly in elderly and young female population. Vitamin D supplementation may be recommended predominantly in winter and summer in this population.