Norwegian study: the vitamin has an antibiotic effect on the immune system
Vitamin D deficiency is likely to blame for the flu epidemic that broke out last week in the Netherlands. The winter months are generally characterised by significantly low levels of this vitamin due to inadequate solar radiation. Research conducted by Norwegian scientists into flu epidemics specifically points to the presence of vitamin D in the body as being a crucial factor.
20 – 600 times more deaths
According to the study, these flu epidemics experience a steep rise in infection and mortality rates as soon as exposure to sunlight (and the corresponding synthesis of vitamin D) drops. This is not only true of the outbreak of flu epidemics but also of the way in which they unfold. Seasonal differences are particularly apparent in the number of deaths. In winter, when vitamin D deficiency is at its greatest, the number of deaths is 20 to 600 times higher than during a summer epidemic, the Norwegian study reveals.
Inadequate sun exposure
“Vitamin D acts as an antibiotic and strengthens the immune system. UV radiation exposure stimulates the production of vitamin D in the skin. In the winter months, when the sun’s zenith is too low in the sky for vitamin D synthesis to take place, the body’s vitamin D level drops, as a result of which its protective effect is unable to fully develop”, explains Professor Johan Moan. In the study, scientists at the University of Oslo examined data on flu epidemics from Sweden, Norway, the United States, Singapore and Japan. They compared the infection and mortality rates for each month with the intensity of UV radiation exposure.
“The seasonality of pandemic and non-pandemic influenzas: the rolesof solar radiation and vitamin D”, Asta Juzeniene, Li-Wei Ma, Mateusz Kwitniewski, Georgy A.Polev, Zoya Lagunova, Arne Dahlback and Johan Moan.
Source: The Sunlight Research Forum