Darker skin types and elevated BMI are important risk factors for vitamin D deficiency in subjects with atopic dermatitis (AD).  This highlights the possibility that seasonality and locale may be potent contributors to cathelicidin induction through their effect on steady state 25OHD levels.  Subjects with AD have defects in antimicrobial peptide (AMP) production possibly contributing to an increased risk of infections. In laboratory models, vitamin D can alter innate immunity by increasing AMP production.  This was a multi-centre, placebo-controlled, double-blind study in 30 subjects with AD, 30 non-atopic subjects, and 16 subjects with psoriasis. Subjects were randomized to receive either 4000 IU of cholecalciferol or placebo for 21 days. At baseline and day 21, levels of 25-hydroxyvitamin D (25OHD), cathelicidin, HBD-3, IL-13, and Eczema Area and Severity Index (EASI) and Rajka-Langeland scores were obtained.  At baseline, 20% of AD subjects had serum 25OHD below 20 ng/mL. Low serum 25OHD correlated with increased Fitzpatrick Skin Type and elevated BMI, but not AD severity. After 21 days of oral cholecalciferol, mean serum 25OHD increased, but there was no significant change in skin cathelicidin, HBD-3, IL-13 or EASI scores.  Given the molecular links between vitamin D and immune function, further study of vitamin D supplementation in subjects with AD is warranted.  See T.R. Hata et al. (2014).

Two hundred eighty (280) healthy individuals (women and men 60–79 years old) were given prasterone 50 mg, or placebo, orally, daily for a year in a double-blind, placebo-controlled study.  Bone turnover improved selectively in women >70 years old, as assessed by the dual-energy x-ray absorptiometry (DEXA) technique and the decrease of osteoclastic activity.  A significant increase in most libido parameters was also found in these older women.  Improvement of the skin status was observed, particularly in women, in terms of hydration, epidermal thickness, sebum production, and pigmentation. A number of biological indices confirmed the lack of harmful consequences of 50 mg / day prasterone administration for one year, also indicating that this kind of replacement therapy normalized some effects of aging.  No potentially harmful accumulation of DHEAS and active steroids was recorded.  Besides the reestablishment of a concentration of DHEAS characteristic of more youthful patients, a small increase of testosterone and estradiol was noted, particularly in women, and may be involved in the significantly demonstrated physiological–clinical manifestations reported. The authors, however, caution, “The commercial availability of DHEA outside the regular pharmaceutical–medical network in the United States creates a real public health problem.”  Baulieu, Eitienne Amile et al., Dehydroepiandrosterone (DHEA), DHEA Sulfate, and aging: Contribution of the DHEAge Study to a sociobiomedical issue, PNAS 8:4279-84 (2000)