Vitamin D - Some Associations

Vitamin D - Some Associations

The volume of research on Vitamin D is simply astounding. Deficiency of vitamin D has been linked to a wide range of conditions including mood, behavior, obesity, cancer, heart disease and overall mortality.

Below are some studies illustrating why you should test and keep your vitamin D in the top end of the normal range, as well as some non-cancer conditions associated with low vitamin D levels.

Vitamin D and Depression in Young Women

Low vitamin D levels are linked to depression - another reason to test and replenish your vitamin D. If your doctor isn't testing it, you can get an inexpensive test kit from the Vitamin D Council.

"OSU researchers found that young women with lower levels of vitamin D were more likely to have clinically significant depressive symptoms over the course of a five-week study, lead author David Kerr said. The results were consistent even when researchers took into account other possible explanations, such as time of year, exercise and time spent outside."


A link to a summary article is here. A link to the research article is here.


Alzheimers Risk Doubled With Low Vitamin D


An important study as elderly are one of the populations most at risk of being vitamin D deficient. This study checked the vitamin D levels and than followed over 1600 healthy adults (no dementia or cardiovascular disease) to see what the effect of vitamin D levels were on their getting dementia. The results were very strong - more than double the risk of developing dementia or Alzheimer's disease in the people with the lowest levels. Another reason to check your levels and get them up to the high normal range.

"Results: During a mean follow-up of 5.6 years,...the multivariate adjusted hazard ratios ...for incident all-cause dementia in participants who were severely 25(OH)D deficient (<25 nmol/L) and deficient (≥25 to <50 nmol/L) were 2.25 ... and 1.53...compared to participants with sufficient concentrations (≥50 nmol/L). ... the risk of all-cause dementia and Alzheimer disease markedly increased below a threshold of 50 nmol/L.

Conclusion: Our results confirm that vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer disease.


A link to a summary article is here. A link to the research article is here.


Weight Loss Easier With Vitamin D

Credit - Alan Cleaver

Image Credit - Alan Cleaver

It is known that obesity is associated with deficiency of vitamin D. This study looked at whether supplementing vitamin D would help with weight loss. The results were somewhat mixed, but in a way that helps us understand how to use vitamin D properly.

There was actually no difference in weight loss between the group that took vitamin D and those that didn't, however the people that took vitamin D and got repleted, as in their levels rose into the normal range, did experience more weight loss, about 50% more than the placebo group.

Looking at the study, a large issue is that all the women in the trial were deficient, with levels between 11 - 31 ng/ml. They only dosed the women with 2,000IU/day of vitamin D, which is a relatively low dosage - in this trial it only increased the vitamin D levels by 13.6 points over a 12 month period. That means that many of the women didn't even get back into the low normal range and not surprisingly they didn't have any positive effect, while those that did come into the normal range, did.

If you've been following any of my writings on vitamin D, you know the key is to test and replete - people need different dosages to raise their levels, so using a standard dose is never correct. I happen to be fairly viramin D resistant, and 5,000 IU/day barely brings me up 10 points in a  year.

Another exciting finding is that women who took their vitamin D showed a drop in C-reactive protein, a blood test marker of inflammation. This means that vitamin D can positively effect some of the metabolic alterations associated with obesity.

"“An overweight person’s body is in a state of chronic inflammation and all of these inflammation proteins that the body produces can cause things like elevated risk for cancer and diabetes,” said Catherine Duggan, Ph.D., principal staff scientist with the Fred Hutch Cancer Research Center’s Public Health Sciences Division. “Vitamin D helped with that. It could make the condition of being overweight less stressful on the body.”

A link to a summary article is here. A link to the research article is here.

Vitamin D and Mortality

Another in a long line of studies on high Vitamin D levels leading to longer life.  This one is wonderful in that it shows that much higher levels than proviously thought are safe and protective.

Normal levels of vitamin D are considered 30-100 which is a far too wide a range. I've been recommending 60-80 as optimal range, and this study says going up to the 90-100 range is the place to be. Most doctors, based on the 'normal' range, are telling people that 30 is fine, which is clearly not the case if you want to decrease cardiovascular disease, respiratory disease, fractures, and well, death.

If fact, the study showed a 44% reduced risk of deaths for the highest levels of vitamin D compared to the lowest.

A link to the full article is here.

Genetically low vitamin D concentrations and increased mortality

Another in what's becoming a common theme - this time in a study with over 95,000 people. Those with the lowest levels had increases in all causes of death, including cancer.

Every 20 point decrease in vitamin D level:
increases overall mortality/death by 19% including
increases cardiovascular deaths by 18%
increases cancer risk by about 12%,
increases all other deaths by 27%

A link to a summary article is here. A link to the research article is here.