for depression, dementia and diabetes
by Dr. Mercola
Vitamin D receptors appear in a wide variety of brain tissue early in the fetal development and activated vitamin D receptors increase nerve growth in your brain. Researchers believe that optimal vitamin D levels may enhance the amount of important chemicals in your brain and protect brain cells by increasing the effectiveness of the glial cells in nursing damaged neurons back to health. Vitamin D may also exert some of its beneficial effects on your brain through its anti-inflammatory and immune-boosting properties.
Vitamin D deficiency drastically raises your risk for dementia
According to one recent study, seniors who have low vitamin D levels may double their risk of dementia and Alzheimer’s disease. Specifically, compared to those with vitamin D levels in the normal range:
Those with low levels had a 53% increased risk for dementia and a 70% higher risk of Alzheimer’s.
Severely deficient individuals had a 125% higher risk for dementia and 120% higher risk for Alzheimer’s.
As noted by the authors, “This adds to the ongoing debate about the role of vitamin D in nonskeletal conditions.”
The link between depression and dementia
Other recent research has found links between depression and dementia and between vitamin D deficiency and depression. One eight-year-long study from Rush University Medical Center found that higher levels of depression translated into greater risk for dementia later on. The severity of the depression was also linked to the speed of memory decline – the worse the depression, the faster the decline in memory. According to lead researcher Robert S. Wilson, “These findings are exciting because they suggest depression truly is a risk factor for dementia and if we can target and prevent or treat depression and causes of stress, we may have the potential to help people maintain their thinking and memory abilities into old age.”
Studies point to the fact that low vitamin D levels also predispose you to depression so the links between vitamin D, dementia and depression indeed appear to be quite real.
In essence, vitamin D deficiency raises your risk of both depression and dementia so the fact that depressed individuals have a higher risk of dementia then becomes rather logical – but the root of the problem is likely to be a lack of vitamin D, not depression in and of itself.
Vitamin D deficiency predisposes you to depression
In one previous study, seniors with the lowest levels of vitamin D were found to be 11 times more prone to be depressed than those who had normal levels. More recent research was discussed in a Times Online article: “The Amsterdam research, which tracked over 1,200 people aged 65 to 95, showed that blood vitamin D levels were 14% lower in individuals with major and minor depression compared with non-depressed participants.
A study in the United States indicated that… people with vitamin D levels below 20 ng/mL had an 85% increased risk of depression compared to those with vitamin D levels greater than 30 ng/mL.”
Vitamin D deficiency has long been associated with Seasonal Affective Disorder (SAD) and in 2007 researchers noted that vitamin D deficiency is associated with depression and fibromyalgia. A double-blind randomized trial published in 2008 also concluded, “It appears to be a relation between serum levels of 25(OH)D and symptoms of depression. Supplementation with high doses of vitamin D seems to ameliorate these symptoms indicating a possible causal relationship.”
Vitamin D may reduce depression and diabetic pain
Vitamin D supplementation has been found to reduce both depression and diabetic pain. Here, researchers assessed how vitamin D supplementation affected women with type 2 diabetes who were also diagnosed with depression. At the outset of the study, 61% of participants reported neuropathic pain – shooting or burning pain in their legs and feet; 74% reported numbness and tingling in their extremities. The participants were given 50,000 IUs of vitamin D2 once a week for six months. At follow-up, both depression and pain scores had improved.
According to lead researcher Todd Doyle, Ph.D., vitamin D supplementation “…is a promising treatment for both pain and depression in type 2 diabetes.” However, I would note that you’d probably get even better results using vitamin D3 rather than prescription D2. In fact, previous research suggests vitamin D2 might do more harm than good in the long term.
Optimizing your Vitamin D also reduces your risk of diabetes
Bringing the focus of this article full circle is research showing that vitamin D may also play a role in type 2 diabetes so now we have a number of cross-links between vitamin D and dementia, depression and diabetes. One Indian study found that vitamin D and calcium supplementation, in combination with exercise, can aid prediabetic individuals by preventing the progression into full blown diabetes.
Since exercise is one of the most effective ways to improve your insulin and leptin sensitivity, this certainly makes sense and may make it more difficult to ascertain which of the two factors – vitamin D or exercise – had the greatest impact. Either way, both are part and parcel of diabetes prevention so the results still speak to the power of simple lifestyle modifications.
As noted by Nephrology News, “Vitamin D deficiency has been linked to prediabetes, which is a blood glucose, or sugar, level that is too high but not high enough to be considered diabetes. It is unclear, however, if bringing low vitamin D blood levels to normal through supplementation will affect progression to diabetes.
In the new study, every unit increase in vitamin D level after supplementation of the vitamin decreased the risk of progression to diabetes by 8%…
‘Without healthy lifestyle changes, nothing works to prevent diabetes in at-risk individuals,’ said lead author Deep Dutta, MD, DM… ‘However, our results are encouraging because the addition of vitamin D and calcium supplements is easy and low in cost.’”
Here, a vitamin D level below 30 ng/ml was considered insufficient. All participants in the study were prediabetic. The treatment group received a once-weekly dose of 60,000 IUs of vitamin D3 along with 1,250 milligrams (mg) of calcium carbonate daily, for eight weeks. A second group received only the calcium supplement. Both groups were advised to get 30 minutes of daily exercise. More than two years worth of follow-up revealed:
Just under 11% of those receiving both vitamin D3 and calcium became diabetic while 26.5% of the calcium-only group developed diabetes.
Blood sugar levels normalized in over twice as many of those in the vitamin D/calcium group, compared to the calcium-only group (41.8% versus 20.4% respectively.)
As noted in a recent MedicineNet article, 60% of seniors seen in emergency rooms across the US are either malnourished or at risk for malnutrition – despite 95% of them having primary care physicians and 96% having health insurance and being otherwise mentally competent… Vitamin D sufficiency is important both when it comes to preventing depression and pain, but a vast majority of seniors are also vitamin D deficient. So here again we see how a vicious cycle can be set into motion by vitamin D deficiency.
How to optimize your vitamin D level
When it comes to vitamin D, you want to be in the “optimal” range, not the “normal” one. Based on the evaluation of healthy populations that get plenty of natural sun exposure, the optimal range for general health appears to be somewhere between 50 and 70 ng/ml.
From Vitamin D for Depression, Dementia, and Diabetes http://articles.mercola.com/sites/articles, August 21, 2014.