Background In the European population of northern climes poses the deficiency of vitamin D (vitD) a frequent problem, especially in autumn and winter1,2. On the other hand it is difficult to supply a necessary dose of vitD in a diet1. The substitution in case of deficiency of vitD occurs principally orally3.
Objectives The aim of this pilot project was to investigate, if 1) an UV-B-stimulus and 2) a diet rich in vitD have an influence on vitD level in autumn and winter months.
Methods 20 healthy female subjects (age: 21-25 years, UV skin types: I - III ) received 3 whole body irradiation with an solar simulated UV-B-stimulus on 3, not successive days, within one week in winter 2011/2012. The dose of the UV-B-stimulus came to 40%, 60% and 75% of the minimal erythema dose (MED) according to UV skin type classification. The level of vitD-metabolites, 25-hydroxy-vitD (25-OH-vitD) and 1.25-Dihydroxy-vitD (1.25-diOH-vitD) were measured on day (d) 1, 8, 36 and 50 (before the irradiation, 3 d, 4 and 6 weeks after the irradiation). A questionnaire including food examples rich of vitD has been enquired on d1.
Results The level of both vitD-metabolites increased significantly on d8 (25-OH-vitD - p<0,001 and 1.25-diOH-vitD – p=0,009). On d36 and d50 the level of 25-OH-vitD was also higher than baseline level ( p < 0,001 on d36, p = 0,043 on d50). There was no correlation between a diet rich in vitD and the beginning level of 25-OH-vitD (k=0,17).
Conclusions Calculated whole body UV-B-irradiation resulted in a significant and long-lasting increase of the level of vitD. A correlation between a diet rich in vitD and the beginning level of 25-OH-vitD couldn’t be shown. It is necessary to investigate if UV-B-stimulus could be used as an alternative to an oral substitution in case of deficiency of vitD.
Referenzwerte für die Nährstoffzufuhr. Vitamin D. Deutsche Gesellschaft für Ernährung (DGE), 1. Auflage, 4. korrigierter Nachdruck 2012
Webb AR, Engelsen O, Calculated ultraviolet exposure levels for a healthy vitamin D status. Photochem Photobiol, 2006;821:697-703
Chandra P, Wolfenden LL, Ziegler TR et al Treatment of vitamin D deficiency with UV light in patients with malabsorption syndromes: a case series. Photodermatol Photoimmunol Photomed 2007;5:179-185
Disclosure of Interest None Declared