Neuere Studien zum Nutzen der Vitamin D-Einnahmezusammengestellt von D
Die Autoren einer randomisierten Studie haben bei Schulkindern untersucht, ob das Risiko, an einer durch den Arzt bestätigten Grippe vom Typ Influenza A zu erkranken, durch die Einnahme von Vitamin D Präparaten reduziert werden kann.
Zwischen Dezember 2008 und März 2009 nahmen 334 Schulkinder an der randomisierten, placebokontrollierten Doppelblindstudie teil. Täglich nahmen sie entweder 1200 IU Vitamin D3 oder Placebo ein. Primärer Endpunkt war die Influenza A-Inzidenz, bestätigt durch Antigentests im nasopharyngealen Abstrich. In der Vitamin D Gruppe betrug die Influenza-Inzidenz 10.8% und in der Placebogruppe 18.6% (Relatives Risiko 0.58, p=0.04). Am stärksten war der präventive Nutzen von Vitamin D3 bei Kindern, welche keine anderen Vitamin D Präparate einnahmen und welche vor dem dritten Lebensjahr nicht in einer Kinderkrippe waren (RR je 0.36 für beide Gruppen). Auch bei Kindern mit Asthma war die Influenza-Inzidenz in der Vitamingruppe signifikant geringer (2 vs 12 Kinder, RR 0.17, p=0.006). Konklusion der Autoren: Diese Resultate sprechen für einen signifikanten Nutzen von Vitamin D3 Präparaten zur Prävention der saisonalen Grippe.
Division of Infectious Diseases and Hospital Epidemiology, Department of Medicine, University Hospital of Zurich, Zurich, Switzerland. Nicolas.Mueller@usz.chAbstractOBJECTIVES: To evaluate the prevalence of 25-hydroxyvitamin D [25(OH)D] deficiency in HIV-positive patients, a population at risk for osteoporosis.
DESIGN: Retrospective assessment of vitamin D levels by season and initiation of combined antiretroviral therapy (cART).
METHODS: 25(OH)D was measured in 211 HIV-positive patients: samples were taken before initiation of cART from February to April or from August to October as well as 12 (same season) and 18 months (alternate season) after starting cART. 1,25-Dihydroxyvitamin D [1,25(OH)2D] was measured in a subset of 74 patients. Multivariable analyses included season, sex, age, ethnicity, BMI, intravenous drug use (IDU), renal function, time since HIV diagnosis, previous AIDS, CD4 cell count and cART, in particular nonnucleoside reverse transcriptase inhibitor (NNRTI) and tenofovir (TDF) use.
RESULTS: At baseline, median 25(OH)D levels were 37 (interquartile range 20-49) nmol/l in spring and 57 (39-74) nmol/l in the fall; 25(OH)D deficiency less than 30 nmol/l was more prevalent in spring (42%) than in fall (14%), but remained unchanged regardless of cART exposure. In multivariable analysis, 25(OH)D levels were higher in white patients and those with a longer time since HIV diagnosis and lower in springtime measurements and in those with active IDU and NNRTI use. 1-Hydroxylation rates were significantly higher in patients with low 25(OH)D. Hepatitis C seropositivity, previous AIDS and higher CD4 cell counts correlated with lower 1,25(OH)2D levels, whereas BMI and TDF use were associated with higher levels. In TDF-treated patients, higher 1,25(OH)2D correlated with increases in serum alkaline phosphatase.
CONCLUSION: Based on the high rate of vitamin D deficiency in HIV-positive patients, systematic screening with consideration of seasonality is warranted. The impact of NNRTIs on 25(OH)D and TDF on 1,25(OH)2D needs further attention.PMID: 20168200 [PubMed - in process]
