Epidemiology Both high and low levels of blood vitamin D are associated with a higher prostate cancer risk: A longitudinal, nested case-control study in the Nordic countries Pentti Tuohimaa 1 *, Leena Tenkanen 2, Merja Ahonen 1, Sonja Lumme 2, Egil Jellum 3, Göran Hallmans 4, Pär Stattin 5, Sverre Harvei 6, Timo Hakulinen 7, Tapio Luostarinen 7, Joakim Dillner 8, Matti Lehtinen 9, Matti Hakama 10 1Medical School, University of Tampere, Tampere, Finland 2Helsinki Heart Study, Helsinki, Finland 3Institute of Clinical Biochemistry, Rikshospitalet, Oslo, Norway 4Cancer Registry of Norway, Montebello, Oslo, Norway 5Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden 6Department of Urology, Umeå University Hospital, Umeå, Sweden 7Finnish Cancer Registry, Helsinki, Finland 8Department of Medical Microbiology, MAS University Hospital, Malmö, Sweden 9National Public Health Institute, Helsinki, Finland 10Institute of Public Health, University of Tampere, Tampere, Finland email: Pentti Tuohimaa (Pentti.Tuohimaa@uta.fi) *Correspondence to Pentti Tuohimaa, Medical School, FIN-33014 University of Tampere, Tampere, Finland Fax: +358-3-215-6170 Abstract Vitamin D inhibits the development and growth of prostate cancer cells. Epidemiologic results on serum vitamin D levels and prostate cancer risk have, however, been inconsistent. We conducted a longitudinal nested case-control study on Nordic men (Norway, Finland and Sweden) using serum banks of 200,000 samples. We studied serum 25(OH)-vitamin D levels of 622 prostate cancer cases and 1,451 matched controls and found that both low (19 nmol/l) and high (80 nmol/l) 25(OH)-vitamin D serum concentrations are associated with higher prostate cancer risk. The normal average serum concentration of 25(OH)-vitamin D (40-60 nmol/l) comprises the lowest risk of prostate cancer. The U-shaped risk of prostate cancer might be due to similar 1,25-dihydroxyvitamin D3 availability within the prostate: low vitamin D serum concentration apparently leads to a low tissue concentration and to weakened mitotic control of target cells, whereas a high vitamin D level might lead to vitamin D resistance through increased inactivation by enhanced expression of 24-hydroxylase. It is recommended that vitamin D deficiency be supplemented, but too high vitamin D serum level might also enhance cancer development. International Journal of Cancer Volume 108, Issue 1 , Pages 104 - 108 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.