The recent press comment on vitamin D made my heart sink. The summary is much more measured, and certainly the paper does not warrant the press headlines; maybe the author made statements . . . - I do not know.
The paper reports that many studies associate higher vitamin D with lower occurrence of many diseases.
They failed to manage to link fairly modest supplementation to change in disease profile, which is not altogether surprising for a variety of reasons, including that maybe the levels of supplementation tried were insufficient.
It is very clear that increasing numbers of people are vitamin D deficient; maybe increasing numbers have poor digestion too, but none of this alters the facts that there are only two way to get high level of vitamin D sunshine or supplementation, (even fish at every meal will not provide the sort of vitamin D levels achieved with modest sun exposure, without sunscreen when UVB can penetrate the atmosphere etc etc) and logically if you are not absorbing it or using more because the body is under stress, then surely the answer is more vitamin D, not less ?????? which brings us back to a choice between sunshine or supplementation - there is no other way - and for most the luxury of stripping off a good proportion of our clothes for a little siesta in the sun at midday is not in reality an option, even if the sun obliges and the skies are not too smogy . . . the reality is supplementation may not be optimal but other than sun it is the only "game in town".
Unfortunately I have not seen the full paper as yet as it is expensive to look at them on a regular basis.
5o micrograms=1000 iu is not going to have a huge effect on vitamin d levels as the table on the Grass Roots site shows. http://grassrootshealth.net/ (20 nanograms =50nmol/l), and according to the papers they drew together health benefits are not seen until blood levels get into the 40ng/l +
http://grassrootshealth.net/media/do...art_032310.pdf
An alternate conclusion might have been are there other reasons why people who are supplementing are unexpectedly low in vitamin D if that is what is being implied; do people have poor digestion and so are not absorbing properly / and or were participants taking the supplements regularly (according to Dr Holick by their own admission in one trial no) / and or are higher doses are needed to see significant effect / or is this in any was a reflection in part that the growing number who are obese have a higher vitamin D requirement / or that sun exposure sunscreen blocker use is rising / or dairy intake and or other foods that contain vitamin D is falling / and as mentioned in the paper might those who have illness sub-clinical or full blown illnesses may use more vitamin D . . .
There really does need to be a more measured way of communicating scientific reports to the public - no wonder people are confused - more importantly inaccurate communication will have subtle but important health consequences for a large number of people
Vitamin D status and ill health: a systematic review
Prof Philippe Autier MD a b Corresponding AuthorEmail Address, Prof Mathieu Boniol PhD a b, Cécile Pizot MSc a, Prof Patrick Mullie PhD a c
Summary
Low serum concentrations of 25-hydroxyvitamin D (25[OH]D) have been associated with many non-skeletal disorders. However, whether low 25(OH)D is the cause or result of ill health is not known. We did a systematic search of prospective and intervention studies that assessed the effect of 25(OH)D concentrations on non-skeletal health outcomes in individuals aged 18 years or older. We identified 290 prospective cohort studies (279 on disease occurrence or mortality, and 11 on cancer characteristics or survival), and 172 randomised trials of major health outcomes and of physiological parameters related to disease risk or inflammatory status.
Investigators of most prospective studies reported moderate to strong inverse associations between 25(OH)D concentrations and cardiovascular diseases, serum lipid concentrations, inflammation, glucose metabolism disorders, weight gain, infectious diseases, multiple sclerosis, mood disorders, declining cognitive function, impaired physical functioning, and all-cause mortality. High 25(OH)D concentrations were not associated with a lower risk of cancer, except colorectal cancer. Results from intervention studies did not show an effect of vitamin D supplementation on disease occurrence, including colorectal cancer. In 34 intervention studies including 2805 individuals with mean 25(OH)D concentration lower than 50 nmol/L at baseline supplementation with 50 μg per day or more did not show better results. Supplementation in elderly people (mainly women) with 20 μg vitamin D per day seemed to slightly reduce all-cause mortality. The discrepancy between observational and intervention studies suggests that low 25(OH)D is a marker of ill health. Inflammatory processes involved in disease occurrence and clinical course would reduce 25(OH)D, which would explain why low vitamin D status is reported in a wide range of disorders. In elderly people, restoration of vitamin D deficits due to ageing and lifestyle changes induced by ill health could explain why low-dose supplementation leads to slight gains in survival.