http://www.digitaljournal.com/life/health/op-ed-vitamin-d-deficiency-increases-alzheimer-s-dementia-risk/article/395674

Op-Ed: Vitamin D deficiency increases Alzheimer’s, dementia risk

Posted Aug 8, 2014 by Paul Wallis
In a surprise finding, researchers at University of Exeter Medical School have proven a link between Vitamin D deficiency and a massively increased risk of dementia. Findings showed a huge discrepancy in risk for those severely deficient in the vitamin.
Alzheimer's  caused by toxic proteins that destroy brain cells  is a currently incurable and fa...
Alzheimer's, caused by toxic proteins that destroy brain cells, is a currently incurable and fatal degenerative disease
Sebastien Bozon, AFP/File
Science Daily:
The team studied elderly Americans who took part in the Cardiovascular Health Study. They discovered that adults in the study who were moderately deficient in vitamin D had a 53 per cent increased risk of developing dementia of any kind, and the risk increased to 125 per cent in those who were severely deficient.
Similar results were recorded for Alzheimer's disease, with the moderately deficient group 69 per cent more likely to develop this type of dementia, jumping to a 122 per cent increased risk for those severely deficient.
These findings are extremely significant. These diseases are widespread in the community, and tracking risk factors has been particularly difficult for many years.
The study also found evidence that there is a threshold level of Vitamin D circulating in the bloodstream below which the risk of developing dementia and Alzheimer's disease increases. The team had previously hypothesized that this might lie in the region of 25-50 nmol/L, and their new findings confirm that vitamin D levels above 50 nmol/L are most strongly associated with good brain health.
Turning sci-speak into consumer-speak
A brief sidetrack, here:
For a spectacularly unhelpful description of the measurement of nmol, see this link.
For an equally unhelpful method of understanding the term “mole”, from which nmol, or nano moles, is derived, see this link to Wikipedia, which says:
The number of molecules in a mole (known as Avogadro's constant) is defined such that the mass of one mole of a substance, expressed in grams, is exactly equal to the substance's mean molecular mass. For example, the mean molecular mass of natural water is about 18.015, so one mole of water is about 18.015 grams. Making use of this equation considerably simplifies many chemical and physical computations.
Grams? One H20 atom weighs 18 grams? No wonder plumbers are such happy people.
Just define the measurements, idiots. Commercially available doses of Vitamin D are also usually given in IU, not nmol, to start with.
Converting IU into anything is also damn near impossible, according to Online Conversions.com:
…What this means is that IU is dependent on the potency of the substance, and each substance would have a different IU to milligram conversion. For example, 1000 IU of Vitamin C would have a different weight than 1000 IU of Vitamin A
Since each substance would have a different conversion ratio, we cannot put up a conversion for IU to milligrams that covers everything, or even most things. Just too many different substances.
The site then suggests you ask your pharmacist. Is it really so damn difficult to translate a measurement into a meaningful statement of some possible use to consumers?
Meanwhile, back on topic
Science Daily defines the Vitamin D sources and issues:
Vitamin D comes from three main sources -- exposure of skin to sunlight, foods such as oily fish, and supplements. Older people's skin can be less efficient at converting sunlight into Vitamin D, making them more likely to be deficient and reliant on other sources. In many countries the amount of UVB radiation in winter is too low to allow vitamin D production.
This discovery could save people from years of misery and fear. It could also save the world billions in treatment costs, if it works as a preventative measure. I would suggest that chemistry get off its formulaic backside and come up with a more intelligible form of measurement for therapeutic doses, though.