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Matti Narkia

Daily duration of vitamin D synthesis in human skin with relation to latitude, total oz... - 1 views

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    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.
Natural Skincare

Natural Skin Care Products - 1 views

I always want my skin to look fair and natural. I have been using many skin care products, yet, I obtain no change. My skin did not even improve. I am looking for a natural skin care product that...

natural skin care

started by Natural Skincare on 14 Sep 11 no follow-up yet
Matti Narkia

Geographic variation of prostate cancer mortality rates in the United States: Implicati... - 0 views

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    Geographic variation of prostate cancer mortality rates in the United States: Implications for prostate cancer risk related to vitamin D. Grant WB. Int J Cancer. 2004 Sep 1;111(3):470-1; author reply 472. No abstract available. PMID: 15221981 10.1002/ijc.20220 The implications of our results and those of Tuohimaa et al.[1] include the following. Vitamin D supplementation should be undertaken in wintertime, a period when it is impossible to produce vitamin D by solar UVB exposure in northeastern states.[13] Given these new results, the optimal vitamin D intake and production and serum 25(OH)-vitamin D3 levels for prostate cancer appear to be lower than for other cancers. However, when developing guidelines for vitamin D fortification, many factors should be included in the analysis, including all of the potential health benefits and possible risks of vitamin D, as well as age, sex, residence, child-bearing status, etc.[14] Also, the suggestion that daily vitamin D3 supplement doses of 100 g (4,000 IU)/day are safe[15] should be reexamined. Finally, in terms of preventing prostate cancer, more attention should be given to diet, which has the greatest environmental impact on risk of prostate cancer, with animal products being important risk factors and vegetable products, especially onions and other allium family members, being important risk-reduction factors.[16]
Matti Narkia

Vitamin D and skin physiology: a D-lightful story - JBMR Online - Journal of Bone and M... - 0 views

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    Vitamin D and skin physiology: a D-lightful story. Holick MF, Chen TC, Lu Z, Sauter E. J Bone Miner Res. 2007 Dec;22 Suppl 2:V28-33. PMID: 18290718 doi: 10.1359/jbmr.07s211 Very few foods naturally contain vitamin D, and those that do have a very variable vitamin D content. Recently it was observed that wild caught salmon had between 75% and 90% more vitamin D(3) compared with farmed salmon. The associations regarding increased risk of common deadly cancers, autoimmune diseases, infectious diseases, and cardiovascular disease with living at higher latitudes and being prone to vitamin D deficiency should alert all health care professionals about the importance of vitamin D for overall health and well being. Humans have depended on sunlight for their vitamin D requirement. The impact of season, time of day, and latitude on vitamin D synthesis is well documented.(2,3) We now report that altitude also has a dramatic influence on vitamin D3 production and that living at altitudes above 3500 m permits previtamin D3 production at a time when very little is produced at latitudes below 3400 m. It was surprising that, at 27° N in Agra (169 M), little previtamin D3 production was observed. However, there was significant air pollution that caused a haze over the city. It is likely the ozone and other UVB-absorbing pollutants in the air prevented the solar UVB photons from reaching the earth's surface to produce previtamin D3.
Matti Narkia

The Daily Lipid: Tufts University Confirms That Vitamin A Protects Against Vitamin D To... - 0 views

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    Tufts University Confirms That Vitamin A Protects Against Vitamin D Toxicity by Curbing Excess Production of Vitamin K-Dependent Proteins Tufts University confirmed my hypothesis that vitamin A protects against vitamin D's induction of renal calcification (kidney stones) by normalizing the production of vitamin K-dependent proteins in December, 2008, without citing my hypothesis or telling me they had confirmed it. I am, of course, very grateful that they thought it significant enough to investigate.
Matti Narkia

VitD Duration of Vitamin D Synthesis in Human Skin - 0 views

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    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
Matti Narkia

VitD-ez Easy Duration of Vitamin D Synthesis in Human Skin - 0 views

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    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.
Matti Narkia

An ecologic study of dietary and solar ultraviolet-B links to breast carcinoma mortalit... - 0 views

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    An ecologic study of dietary and solar ultraviolet-B links to breast carcinoma mortality rates. Grant WB. Cancer. 2002 Jan 1;94(1):272-81. PMID: 11815987 CONCLUSIONS It is hypothesized that animal products are associated with risk for breast carcinoma because they are associated with greater amounts of insulin-like growth factor-1and lifetime doses of estrogen. Vegetable products contain several risk reduction components including antioxidants and phytoestrogens. The association with latitude is very likely because of solar UV-B radiation and vitamin D. Alcohol modulates estrogen's effects on breasts. Fish intake is associated with risk reduction through vitamin D and n-3 oils. These results are consistent with those of many case-control and cohort studies but should be assessed in well designed cohort studies.
Matti Narkia

Sunlight Regulates the Cutaneous Production of Vitamin D3 by Causing Its Photodegradati... - 0 views

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    Sunlight regulates the cutaneous production of vitamin D3 by causing its photodegradation. Webb AR, DeCosta BR, Holick MF. J Clin Endocrinol Metab. 1989 May;68(5):882-7. PMID: 2541158 doi:10.1210/jcem-68-5-882 Vitamin D3 proved to be exquisitely sensitive to sunlight, and once formed in the skin, exposure to sunlight resulted in its rapid photodegradation to a variety of photoproducts, including 5,6-transvitamin D3, suprasterol I, and suprasterol II.suprasterol I, and suprasterol II.
Matti Narkia

Effects of calcium, dairy product, and vitamin D supplementation on bone mass accrual a... - 0 views

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    Effects of calcium, dairy product, and vitamin D supplementation on bone mass accrual and body composition in 10-12-y-old girls: a 2-y randomized trial. Cheng S, Lyytikäinen A, Kröger H, Lamberg-Allardt C, Alén M, Koistinen A, Wang QJ, Suuriniemi M, Suominen H, Mahonen A, Nicholson PH, Ivaska KK, Korpela R, Ohlsson C, Väänänen KH, Tylavsky F. Am J Clin Nutr. 2005 Nov;82(5):1115-26; quiz 1147-8. PMID: 16280447
Matti Narkia

Schematic diagram of cutaneous production of vitamin D and its metabolism and regulatio... - 0 views

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    Schematic diagram of cutaneous production of vitamin D and its metabolism and regulation for calcium homeostasis and cellular growth - Figure 3 from the study Holick MF. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, can
Matti Narkia

The solar UV radiation level needed for cutaneous production of vitamin D3 in the face.... - 0 views

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    The solar UV radiation level needed for cutaneous production of vitamin D3 in the face. A study conducted among subjects living at a high latitude (68 degrees N). Edvardsen K, Brustad M, Engelsen O, Aksnes L. Photochem Photobiol Sci. 2007 Jan;6(1):57-62. Epub 2006 Nov 10. PMID: 17200737
Rose Hip

Age Defying and Organic Skin Care Rosehip Products - 1 views

Since I have multiple chemical allergies, finding a 100% natural skin care product is really difficult. When a friend introduced Rosehip Organic Skin Care pack over 12 months ago, I was a bit skept...

organic skin care

started by Rose Hip on 12 Apr 11 no follow-up yet
Meredith Blige

Proven Very Effective Anti-Snoring Products - 1 views

My husband kept asking me the question "how can I stop snoring" because I always told him that I cannot get enough sleep due to his loud snoring. He was worried that I might get sick, so we searche...

how can I stop snoring

started by Meredith Blige on 25 Oct 11 no follow-up yet
Rachel Renner

Superb Anti-Snoring Device - 1 views

Noiselezz is the best anti-snoring device that I have ever tried. My wife was about to kick me out of our bedroom until I have found KVG Australia's anti-snoring product. Honestly, I have already t...

started by Rachel Renner on 15 Oct 12 no follow-up yet
Roberto Marabe

Custom Manufacture - 0 views

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    One of the leading company cnlab.ca is the manufacture of such nutritional supplements, which at the other hand provides customs manufacturing and OEM service for not only nutritional soft gel products but also tablet, hard gelatin capsules. It is a company of Private label in China who understands the science and cultures of natural health supplements.
Matti Narkia

Environmental factors that influence the cutaneous production of vitamin D -- Holick 61... - 0 views

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    Environmental factors that influence the cutaneous production of vitamin D. Holick MF. Am J Clin Nutr. 1995 Mar;61(3 Suppl):638S-645S. Review. PMID: 7879731
Matti Narkia

Vitamin D fortification of milk products does not resolve hypovitaminosis D in young Fi... - 0 views

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    Vitamin D fortification of milk products does not resolve hypovitaminosis D in young Finnish men. Välimäki VV, Löyttyniemi E, Välimäki MJ. Eur J Clin Nutr. 2007 Apr;61(4):493-7. Epub 2006 Nov 29. PMID: 17136043 doi:10.1038/sj.ejcn.1602550
Meredith Blige

Sleep Apnea Test That Can Be Done at Home - 2 views

I am really pleased with the results of Nasivent Home Apnea Test from StopSnoringNowShop. Because of it, I conveniently underwent a sleep apnea test in my home. After a night sleep using the sleep ...

sleep apnea test

started by Meredith Blige on 21 Jun 11 no follow-up yet
Matti Narkia

Regulation of cutaneous previtamin D3 photosynthesis in man: skin pigment is not an ess... - 0 views

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    Holick, M. F., MacLaughlin, J. A. & Doppelt, S. H. (1981) Factors that influence the cutaneous photosynthesis of previtamin D3. Science 211:590-593 When human skin was exposed to simulated solar ultraviolet radiation, epidermal 7-dehydrocholesterol was converted to previtamin D3. During prolonged exposure to simulated solar ultraviolet radiation, the synthesis of previtamin D3 reached a plateau at about 10 to 15 percent of the original 7-dehydrocholesterol content, and previtamin D3 was photoisomerized to two biologically inert isomers, lumisterol3 and tachysterol3. Increases either in skin melanin concentration or in latitude necessitated increases in the exposure time to simulated solar ultraviolet radiation required to maximize the formation, but not the total content, of previtamin D3. In order of importance, the significant determinants limiting the cutaneous production of previtamin D3 are (i) photochemical regulation, (ii) pigmentation, and (iii) latitude.
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