Tag Archive for: falls

Vitamin D: Stay the Course

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Let’s finish this look at the recent paper on vitamin D (1). As you could read in Thursday’s Memo, they included some curious studies in their review. Let’s take a look.

Mixed-Purpose Studies

Have you ever eaten leftovers? Sure. Did you take all the different leftovers—the spaghetti, the fried rice, the mashed potatoes and gravy—mix them together in a stew or smoothie, and eat them? Probably not. And that’s the primary problem with this review paper: too many different types of studies.

There were enough papers using very high doses of vitamin D administered orally to the elderly that could have been combined. There certainly were enough studies to use only 800 or 1,000 IUs that could have been combined.

It is not the statistics; it’s the physiology and biochemistry. There’s going to be a difference in how the body utilizes 100,000 IUs at one time versus 1,000 IU every day for 100 days. That has to be acknowledged as a possibility. That it wasn’t illustrates a typical problem in these types of studies.

The Pharmaceutical Model

The real weakness of the studies that were included in this review was that the vitamin D was used as a treatment for a disease rather than as a nutritional supplement. What gets lost in translation is that in several studies where vitamin D was used to address low vitamin D levels in the elderly with and without fractures, there was actual improvement in bone-mineral density.

It begs the question: why would you give astronomical doses to healthy people? That’s what they did in communities of elderly residents. Their intentions were good (they wanted to try to prevent fractures and falls), but it’s a lousy approach. Would you give someone a one-month dose of a blood pressure medication? You could kill them. If you’re going to use a vitamin that has robust uses in the body, you have to respect it. They considered it a nutrient, but used it as a drug.

The only issue that I could find with the high doses of vitamin D is that for some reason, they were associated with an increase in falls. That seems inexplicable to me, but it was a consistent observation at high doses of vitamin D. The only reason I would consider it suspect was that in most studies included in the review paper, people self-reported falls. Still, it was there.

The Bottom Line

The overall problem with this review of vitamin D is that the authors considered only a single factor; bone building is dependent on a variety of nutritional factors that were never considered. Most of all, the great majority of the studies didn’t consider the role of exercise: fewer than five of the 81 studies gave any mention to exercise. In order for bones to grow and recover, they must be stressed on a regular basis. There’s no way to come to the conclusions the authors did without that data.

While researchers looked at only a single factor involving the musculoskeletal system, the immune and nervous systems can still benefit from vitamin D even if bones don’t benefit as much as some supplements promise. Vitamin D has also been shown to help mental health and depression. Some day nutrition research will be done correctly, but it wasn’t served very well by this paper or the studies that were included. I found no reason to stop taking vitamin D as a supplement. In fact, it’s time to increase your dosage as the days get shorter and your sunlight exposure decreases.

What are you prepared to do today?

Dr. Chet

 

Reference: DOI:https://doi.org/10.1016/S2213-8587(18)30265-1.

 

A Potpourri of Research on Vitamin D

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Scientists try to follow some strict guidelines when they select studies to be included in a meta-analysis. With that in mind, here’s some of what I found in reviewing the studies. Remember, they were looking at fractures, falls, and bone-mineral densities.

  • The length of the studies ranged from as short as eight weeks to as long as seven years. The most popular study length was one year, second was two years.
  • Most of the studies focused on the elderly. Falling and fractures are obvious concerns for that population. But they also included papers on post-parathyroidectomy patients of all ages, renal transplant patients, and young patients that were HIV positive where falling and fractures were not obvious consequences of the age group.
  • For the most part, they selected studies with vitamin D taken via oral supplements. But they also used cod liver oil, with and without vitamin D, as well as intramuscular injections.
  • This one was just simply puzzling. The range of vitamin D administered to the subjects was as low as 400 IU and as high as 600,000 IU in a single dose. Some gave oral vitamin D at 100,000 IUs four times per year, injections of 300,000 IU and 600,000 IU, and one study administered 300,000 IU in a single oral dose.

You don’t have to have any type of scientific degree to see the problem with the apples-and-oranges selection of the studies. Competent scientists may be able to account for differences statistically to do the analysis, but they can’t account for the varying physiological impacts on the subjects.

I’ll finish this up on Saturday.

What are you prepared to do today?

Dr. Chet

 

Reference: DOI:https://doi.org/10.1016/S2213-8587(18)30265-1.

Update: Vitamin D’s Health Effects

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With all the political headlines last week, an important health headline could have been overlooked. A group of scientists published a paper suggesting vitamin D doesn’t prevent fractures and falls or help increase bone-mineral density, and they recommended that it not be used for that purpose. I’m a strong believer that vitamin D is one of the fundamental supplements we should take, so I took a close look at this paper.

Typically I call this a Research Update, but I’m intentionally not calling it that this time because there’s no new research in this paper. This was a research review paper that included a re-analysis of prior research, some 81 studies. That’s a meta-analysis, a statistical technique that has risen in popularity in the past 10 years. In fact, it really only included research published since 2014, the last time some of these authors did the exact same analysis. Based on the prior research of the statistician involved who was the lead author, I have to believe the math is correct.

The problem is in the selection of the studies. I did something I don’t always do. I examined almost all of the abstracts of the 81 papers that were used in the meta-analysis. It was tedious to say the least. To be blunt, I don’t understand how some of the papers were selected. On Thursday, I’ll give you the run down on the research review part of the paper.

What are you prepared to do today?

Dr. Chet

 

Reference: DOI:https://doi.org/10.1016/S2213-8587(18)30265-1.