Low Vitamin D and Diabetes was first.
Low vitamin D and Dementia is now.
But where is the cause and effect?
Let’s be clear, Vitamin D deficiency is associated with the onset of insulin resistance and diabetes.[i] Yes, the strong association between low vitamin D and the development of insulin resistance and type 2 diabetes is crystal clear.[ii] But it appears that vitamin D is not the “cause” of the insulin resistance; mere vitamin D supplementation is not a magic bullet.[iii] The insulin resistance comes first.
The latest headline, “Low Vitamin D And Dementia” is the result of excited researchers, published in the journal Neurology on August 6th 2014, who describe the link between low vitamin D and dementia onset. But I posit that it is the same associative data as the low vitamin D and Type 2 diabetes – insulin resistance is driving this train too.
In fact – there is some strong data to support the renaming dementia of the Alzheimers type “Diabetes Type 3”. Insulin resistance, as it develops in the brain, results in a lack of proper glucose utilization in the brain cells resulting in the pathology and expression of dementia.[iv] And cause and effect data once again brings us to insulin resistance as primary instigator.[v] Low vitamin D does not cause insulin resistance and type 2 diabetes, and low vitamin D does not cause dementia. It is the insulin resistance driving both the low vitamin D and the dementia onset risk.
Should we all get our vitamin D levels into the upper levels with supplements? No. But vitamin D deficiency is related to insulin resistance, and if uncorrected, high blood sugar and type 2 diabetes is more difficult to reverse. A mere 1,000 iu additional vitamin D is likely to be adequate for nearly everyone. Want to get to what is really important – the underlying cause? Correct the insulin resistance. Turn you body back into the insulin sensitive person you should be.
[i] Khan, H., et al. Vitamin D, type 2 diabetes and other metabolic outcomes: A systematic review and meta-analysis of prospective studies. Proc Nutr Soc. 2013 Feb; 72(1):89–97.
[ii] Tsur, A., et al. Decreased serum concentrations of 25-Hydroxycholecalciferol are associated with increased risk of progression to impaired fasting glucose and diabetes. Diabetes Care. 2013 Feb doi; 10.2337/dc12-1050.
[iii] George, P. S., et al. Effect of vitamin D supplementation on glycemic control and insulin resistance: a systematic review and meta-analysis. Diabet Med. 2012 Aug; 29(8):e142–50.
[iv] Rhode Island Hospital Study Finds Link Between Brain Insulin Resistance and Neuronal Stress in Worsening Alzheimer’s Disease – Neurosciences Institute, Research, RIH. June 26, 2012.
[v] Brain Insulin Resistance Contributes to Cognitive Decline in Alzheimer’s Disease – Penn Medicine. March 23, 2012.