Not sure the link will work but it is a map of prostate cancer prevalency. High in US and Canada. Low in Russia into Asia. So seems actually negatively correlated with Vitamin D deficiency. Higher Vit D deficiency in Asia, but less likelihood of getting prostate cancer? Different pr
opensity to cancer due to ethnic/genetic differences? But wonder how much of that prevalency shown is based simply on higher detection due to screening in the US and Canada which is not widely done elsewhere, and if it were would also find more cases?
From Worldwide status of vitamin D nutrition it seems that the difference is more complicated than northern and southern climate.
Vitamin D deficiency (serum 25(OH)D<25 nmol/l) is highly prevalent in India and China while vitamin D status is better in Japan and South-East Asia. Vitamin D deficiency is very common in the Middle-East and there is a relationship with skin covering clothes and staying outside of the sun. A poor to moderate vitamin D status is also common in Africa, probably caused by the dark skin types and cultural habits of staying outside of the sunshine. Vitamin D status is much better in North America where vitamin D deficiency is uncommon but vitamin D insufficiency (serum 25(OH)D between 25 and 50 nmol/l) is still common. In the United States and Canada milk is usually supplemented with vitamin D and the use of vitamin supplements is relatively common. Vitamin D status in Latin America usually is reasonable but there are exceptions and vitamin D insufficiency still occurs quite often. In Australia and New Zealand a poor vitamin D status was seen in the elderly who were often vitamin D deficient and also in immigrants from Asia. Vitamin D deficiency also occurred in children when the mother was vitamin D deficient. Within Europe, vitamin D status usually is better in the Nordic countries than around the Mediterranean. This may be due to a lighter skin and sun seeking behaviour and a high consumption of cod liver oil in the Northern countries while in Southern Europe people stay out of the sunshine and have a somewhat darker skin.
BB - maybe I will measure my D (out of curiosity) and inform you. As you see above maybe my light skin and the high cod liver oil consumption here maintains it on a normal and healthy level?
Gemlin, I suspect you are correct, it is more complicated than any one factor and your post makes some good points. In fact, it can be quite complicated.
Do you consume- or have taken frequently- cod liver oil? If so, that is a form of supplementation, I'm sure you know. I hope you do measure your D level and let us know. Although, if you have been taking CLO, that means you have been supplementing which should raise your level.
There are some(Mercola) that argue that the vitamin A in CLO defeats the benefits of vitamin D. Though he is supposed to be a member of their group, there are other people(Weston Price Foundation) that argue he has it backwards, and the vitamin A in SOME CLO(it is remove from much CLO these days) is a big help(and more natural), and that vitamin D by itself DEPLETES vitamin A. And they ask Mercola why he has to give so much Vitamin D- thousands of units per day- to get an adequate blood level of Vitamin D, when they can do it with the much lower vitamin D levels seen in CLO?
I have no clue as to who is correct. Risk of excessive (like above 80 or 90) blood levels of vitamin D are mentioned in this article by these pro vitamin D and Cod Liver Oil folks, as well as the need for vitamin A and K2 with the higher levels of Vitamin D, which they claim prevents most of the problems that might arise with massive supplements of vitamin D by itself. /www.westonaprice.org/health-topics/abcs-of-nutrition/update-on-vitamins-a-and-d/
BTW, I have long taken Vitamin K2 with my Vitamin D, and try to eat vitamin A rich foods and sometimes supplement with it, or sometimes take CLO, even though Mercola says I shouldn't. In fact, I have a concoction of high vitamin D/high vitamin A that I have taken for developing colds and lung infections that seems to have performed near miracles in recent years. Having had a couple of battles with pneumonia in years past, I can tell when it is approaching, and this has defeated it early(within hours) several times now. ( I am not recommending that for anyone, it might kill you so DON'T do it!)
This is lengthy and complicated, I will just provide a short quote:/www.westonaprice.org/health-topics/cod-liver-oil/a-response-to-dr-joe-mercola-on-cod-liver-oil/
Weston A Price said...
..........In order for vitamin D to activate the expression of its target genes, it must bind to the vitamin D receptor (VDR) and then combine with the retinoid X receptor (RXR), which is activated by a particular form of vitamin A called 9-cis retinoic acid. Researchers from Spain recently showed that vitamin D can only effectively activate target genes when its partner receptor is activated by vitamin A.
Mercola Statement: The Weston Price Foundation, of which I am an advisory [honorary] member, holds a contradictory view. They believe vitamin D can only effectively target genes when its “partner receptor” is activated by vitamin A. If vitamin A is absent, certain molecules called co-repressors bind to the receptors and prevent vitamin D from functioning. It is their position that cod liver oil is still a highly recommended supplement.
WAPF Response: Dr. Mercola is no longer a member of the Weston A. Price Foundation honorary board. Research does indeed indicate that vitamin D can only effectively target genes when its partner receptor is activated by vitamin A.
Mercola Statement: After reviewing the evidence, I am personally convinced that there is sufficient vitamin A in the current American diet to facilitate sufficient vitamin D activation. This does not appear to be the case in third world countries, where cod liver oil, or some other preformed retinol supplement, would still be useful.
WAPF Response: Please supply us with this evidence. Where does the average American get vitamin A in the modern diet? If vitamin A in the American diet is adequate for vitamin D activation, why are Cannell and Mercola obliged to recommend such high levels of vitamin D—levels much higher than those found in traditional diets—in order to bring serum vitamin D levels into the normal range?................