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ncident invasive breast cancer, geographic location of residence, and reported average time spent outside. Millen AE, Pettinger M, Freudenheim JL, Langer RD, Rosenberg CA, Mossavar-Rahmani Y, Duffy CM, Lane DS, McTiernan A, Kuller LH, Lopez AM, Wactawski-Wende J. Cancer Epidemiol Biomarkers Prev. 2009 Feb;18(2):495-507. Epub 2009 Feb 3. PMID: 19190147 doi: 10.1158/1055-9965.EPI-08-0652 In conclusion, region of residence and geographic solar irradiance are not consistently related to risk of breast cancer and may not be sufficient proxy measures for sunlight/vitamin D exposure. The observed association between time spent outside and breast cancer risk support the hypothesis that vitamin D may protect against breast cancer.

van der Wielen RP, Lowik MR, van den BH, de Groot LC, Haller J, Moreiras O, van Staveren WA (1995) Serum vitamin D concentrations among elderly people in Europe. Lancet 346: 207-210 These findings show that free-living elderly Europeans, regardless of geographical location, are at substantial risk of inadequate vitamin D status during winter and that dietary enrichment or supplementation with vitamin D should be seriously considered during this season.

Half of the patients with an acute hip fracture suffer from hypovitaminosis D: a prospective study in southeastern Finland. Nurmi I, Kaukonen JP, Lüthje P, Naboulsi H, Tanninen S, Kataja M, Kallio ML, Leppilampi M. Osteoporos Int. 2005 Dec;16(12):2018-24. Epub 2005 Aug 24. PMID: 16133642 Half of the patients with a hip fracture suffered from hypovitaminosis D. The situation was worst in institutional and residential care, although there are personnel for taking care of vitamin D supplementation. In the late summer, one-third and in late winter two-thirds of the patients suffered from hypovitaminosis D. The geographical location of Finland indicates extensive efforts to increase the use of vitamin D supplements among elderly.

A few researchers are turning their attention to the sunshine vitamin as a culprit, prompted by the experience of immigrants that have moved from their equatorial country to two northern latitude locations As evidence of widespread vitamin D deficiency grows, some scientists are wondering whether the sunshine vitamin-once only considered important in bone health-may actually play a role in one of neurology's most vexing conditions: autism. The idea, although not yet tested or widely held, comes out of preliminary studies in Sweden and Minnesota. Last summer, Swedish researchers published a study in Developmental Medicine and Child Neurology that found the prevalence of autism and related disorders was three to four times higher among Somali immigrants than non-Somalis in Stockholm. The study reviewed the records of 2,437 children, born between 1988 and 1998 in Stockholm, in response to parents and teachers who had raised concerns about whether children with a Somali background were overrepresented in the total group of children with autism

"Lisa is one of early success stories: a heart scan score of 447 in her early 40's, modest reduction of CT heart scan score three years ago. However, Lisa had a difficult time locating oil-based vitamin D. There has, in fact, been a national run on vitamin D and I'm told that even manufacturers are scrambling to keep up with the booming demand. So, she bought tablets instead and was taking 3000 units per day. She came in for a routine check. Lisa's 25-OH-vitamin D3: 17 ng/ml, signifying severe deficiency, the same as if she were taking nothing at all. (Recall that we aim for 50 ng/ml.) In other words, vitamin D tablets do not work. It is shameful. I see numerous women taking calcium tablets with D--the vitamin D does not work. I've actually seen blood levels of zero on these preparations. "

Vitamin D production in human skin occurs only when UV radiation exceeds a threshold. From simulations of UV irradiances, the VitD www page ( http://zardoz.nilu.no/~olaeng/fastrt/VitD.html) computes the daily duration of dermal vitamin D production at midday when UV radiation exceeds the required threshold. The daily duration depends on latitude, time, total ozone, clouds, aerosols, surface reflectivity and altitude all of which can be specified by the user

Vitamin D production in human skin occurs only when UV radiation exceeds a threshold. From simulations of UV irradiances, the VitD-ez www page ( http://zardoz.nilu.no/~olaeng/fastrt/VitD-ez.html) computes the daily duration of dermal vitamin D production at midday when UV radiation exceeds the required threshold. The VitD-ez www page is a simplified version of the more complex VitD web page ( http://zardoz.nilu.no/~olaeng/fastrt/VitD.html). The simplified VitD-ez www page is convenient for users unfamiliar to radiative transfer modelling, because the model input is limited and more intuitive.

Daily duration of vitamin D synthesis in human skin with relation to latitude, total ozone, altitude, ground cover, aerosols and cloud thickness. Engelsen O, Brustad M, Aksnes L, Lund E. Photochem Photobiol. 2005 Nov-Dec;81(6):1287-90. PMID: 16354110 Vitamin D production in human skin occurs only when incident UV radiation exceeds a certain threshold. From simulations of UV irradiances worldwide and throughout the year, we have studied the dependency of the extent and duration of cutaneous vitamin D production in terms of latitude, time, total ozone, clouds, aerosols, surface reflectivity and altitude. For clear atmospheric conditions, no cutaneous vitamin D production occurs at 51 degrees latitude and higher during some periods of the year. At 70 degrees latitude, vitamin D synthesis can be absent for 5 months. Clouds, aerosols and thick ozone events reduce the duration of vitamin D synthesis considerably, and can suppress vitamin D synthesis completely even at the equator. A web page allowing the computation of the duration of cutaneous vitamin D production worldwide throughout the year, for various atmospheric and surface conditions, is available on the Internet at http://zardoz.nilu.no/~olaeng/fastrt/VitD.html and http://zardoz.nilu.no/~olaeng/fastrt/VitD-ez.html. The computational methodology is outlined here.