Posts Tagged ‘vitamin d’

Vitamin D and Neurologic Disease

Tuesday, July 13th, 2010

Vitamin D has been all the rage for a few years. Ironically, despite the fact that everyone knows that our bodies create vitamin D in response to sunlight and most of us experience mood changes during the darker months, the high likelihood of a link had not been researched.

A study was just published correcting this blatant neglect and it was a very well designed interventional trial to boot. Over 900 elderly women and men were evaluated for evidence of depression and tested for their vitamin D blood level. They were followed for 6 years. At the end of the study women who had low vitamin D levels at the beginning of the study were twice as likely to develop depression. Low vitamin D males were 1.6 times as likely to become depressed.

Multiple Sclerosis has long been linked to vitamin D, with deficiency likely to make people susceptible and supplementation as an effective treatment. The association between vitamin D and MS is clearly important.

Other recent studies have confirmed links between vitamin D levels and various neurologic diseases, including Alzheimer’s. Sceptic that I am, some of those studies do not prove causation to me. I want to know that blood levels were low before the onset of any symptoms because people who are not well, especially if “not well” includes limitations to their mobility or thinking, will tend to go outside less than other people. Consequently they will have relatively lower vitamin D blood levels.

One recent study of Parkinson’s Disease and vitamin D does, fairly well at least, satisfy my skepticism. Finnish scientists analyzed blood of 3,000 individuals sampled between 1978 and 1980. After 30 years they found that individuals with the lowest levels of vitamin D were three times more likely to have developed Parkinson’s compared to those with the highest levels. As the number those developing Parkinson’s was small and the study was not one where vitamin D was given to healthy people to see whether Parkinson’s was prevented by the intervention with vitamin D, there are still some flaws but not enough to discount the findings. As we have often observed links between various environmental toxins and Parkinson’s and vitamin D helps our bodies clear such toxins, a causative connection is certainly possible. Also, as vitamin D has so very many biological effects, it is certainly possible that it might influence the rate of Parkinson’s and other neurologic disease by other means.

As is perfectly obvious at this point, everyone excepting a very few with a couple of rare disease, should make certain that she/he has good levels of vitamin D . In my opinion that means 50 ng/ml or above.


Vitamin D in Pregnancy

Saturday, May 1st, 2010

Forgive me for rattling on about vitamin D, but it is VERY important. The latest news is even more important than usual, and it is notable for at least three reasons, maybe four, if we count the fact that Mother’s Day is fast approaching.

The most meaningful studies are designed as interventional trials, where people are divided into groups, each receiving different treatments, and then their responses analyzed statistically to determine if the treatment had any effect. This study was designed in that way, with women who were pregnant for 12 weeks or more randomly assigned to receive either 400, 2,000 or 4,000 iu of vitamin D a day. Researchers then tracked their risk of major complications of pregnancy, including premature labor, premature birth and infections. The highest dose of vitamin D, 4,000 iu/day, was clearly associated with the lowest rate of complications.

First, this is important because pregnancy complications are serious and common.

Secondly, because showing that doing something has an effect demonstrates cause not just association.

FInally, given official warnings that taking 2,000 iu/day of vitamin D is the safe upper limit, I am impressed that they were able to get the study approved. Human Subjects Committees at research institutions are mandated to block research that endangers the subjects of the trial. For example, 15 years ago, when I conducted the first national survey of alternative medical instruction in US medical schools and family practice residency programs, the Human Subjects Committee at UCSF refused to allow me to resend questionnaires to schools that did not respond to the first one, as they felt that I would be harming them by such a request. Seriously. Thankfully, the particular HSC involved in this case was courageous enough to approve this vitamin D study. As such research is needed and human subjects committee can be ridiculously conservative, this is not a minor event. I find that most patients need well more than the “safe limit” of 2,000 to bring their blood levels up to normal. This “safe limit” is completely wrong and unscientific. It must be changed, and the sooner the better.


Supplement Content and Purity

Thursday, April 29th, 2010

Health advocate Gary Null has provided an unintentional educational lesson for those of us using dietary supplements. Taking one of his own products, he developed vitamin D toxicity. As there have been only a few cases of vitamin D toxicity ever reported, there is an inevitably interesting story behind this announcement.

The story is that his supplement contained 1,000 TIMES the amount of vitamin D it was supposed to. Instead of taking 2,000 iu a day, he was taking 2,000,000 iu day after day for a month. Wow!


Also, a recent independent analysis of St John’s Wort products found that fully one half of those tested were either contaminated with heavy metals (lead, cadmium) or deficient in the active marker compounds essential to the herb’s effects. 12 years ago a similar study found that the majority of products sold as St John’s Wort at health food stores was not actually St John’s Wort.

Please use these as a reminder to make sure that you purchase good supplements that have been analyzed for purity and content. As you can see on my MVM bottles, look for USP certification on vitamins. Purchase the best quality herbs, processed by manufacturers who comply with Good Manufacturing Practices, tested for marker compounds as noted on the label and ideally confirmed by independent testing.


How Vitamin D Helps Asthma

Friday, April 16th, 2010

Although we have lots of evidence showing that vitamin D lowers the risk of many diseases, the lingering concern is that vitamin D levels might simply tell us who was healthier to begin with. In other words, healthy people go outside more often because they are healthy not the other way around.

With the passage of time and completion of the more demanding studies required to determine causation rather than association, vitamin D continues to look every bit as promising. Identifying physiologic pathways important in specific disease and influenced by vitamin D raise our confidence that the effects of D are real.

The latest such discoveries come from National Jewish Health in Denver, a famous center for asthma and allergy research. Studies they conducted of adults and children with asthma have shown that lower D levels are associated with worse asthma symptoms. Reaching further into the “how could that be” side, these studies have shown that vitamin D enhanced anti-inflammatory effects of certain immune cells and accentuated the effectiveness of steroids prescribed to treat asthma. One study found that a certain steroid was 10 times more effective when administered in conjunction with vitamin D.

Even if vitamin D only helped asthmatic patients by reducing their steroid dose, that would be great because, as the “heavy guns” of medical pharmacology, steroids have many nasty adverse effects and those effects are dose-related. However there is excellent cause to believe that D does much more and can help many asthmatics come off of medication entirely.