In this solo presentation, Dr. David Perlmutter discusses the association between low vitamin D levels and increased risk of dementia, particularly Alzheimer’s disease. He references a Neurology cohort study of 1,658 cognitively intact older adults followed for 5.6 years, highlighting that severe vitamin D deficiency (≤25 nmol/L) more than doubled the risk of all‑cause dementia (2.25‑fold) and Alzheimer’s (2.22‑fold), while moderate deficiency (25‑50 nmol/L) raised risk by roughly 53‑69%. Perlmutter explains proposed biological mechanisms: reduced macrophage‑mediated clearance of beta‑amyloid, heightened neuronal apoptosis, and vascular dysfunction. He adds a less‑discussed pathway—vitamin D’s activation of the antimicrobial peptide cathelicidin, which may help the brain clear microbial agents implicated in Alzheimer’s (e.g., Porphyromonas gingivalis, herpes viruses, Chlamydia pneumoniae). The talk underscores vitamin D’s broader hormonal role beyond bone health, cites Dr. Dale Bredesen’s protocol that targets optimal vitamin D levels, and recommends checking blood levels and supplementing with vitamin D3 as a preventive strategy.
Chapters
Hello everyone, Dr. David Perlmutter here. I'd like to talk to you today about the relationship between vitamin D and risk for dementia, and specifically risk for Alzheimer's disease. You know, we've been seeing quite a lot written lately about vitamin D. We see that Dr. Dale Bredesen uses it as part of his Alzheimer's treatment protocol. that he will give vitamin D to get the vitamin D levels by blood testing up to where they need to be. Well, why is this important? Well, in a study published in the journal Neurology, and you'll get the link for that, entitled Vitamin D and the Risk of Dementia and Alzheimer's Disease, these researchers wanted to determine what this relationship was. Is there a relationship between having a low level of vitamin D and subsequently developing Alzheimer's or other form of dementia? They looked at 1,658 elderly individuals who, at the beginning of the study, were free of dementia, cognitively intact. They measured their vitamin D levels and then they followed this group of elderly individuals for several years. They followed them for 5.6 years and here's what they found. Those individuals who had severe— severely deficient levels of vitamin D, meaning 25 nanomoles per liter or less, in other words, their blood level was 25 or less vitamin D, risk was increased 2.25-fold for any form of dementia. If their blood level was between 25 and 50, which we call deficient vitamin D, then their risk was still increased by about 53%. Now, as it relates to Alzheimer's disease specifically, here's what they found. Those who had severely deficient levels, again 25 or less of vitamin D, their risk was increased 2.22-fold and increased by 69% if they were between 25 and 50. So the researchers stated, our results confirm that vitamin D deficiency is associated with a substantially increased risk for all-cause dementia and Alzheimer's disease. And a little bit more. This adds to the ongoing debate about the role of vitamin D in non-skeletal conditions. And what they mean by that is, yeah, we've been talking, or medical researchers have been talking about, yeah, vitamin D is really important for bone health. You know, it's why they put vitamin D in milk, for crying out loud. But we now recognize that vitamin D, which is a hormone and activates more than 250 enzymes throughout the body, does a heck of a lot more than just simply build strong bones. As we now see, it's related to risk for developing dementia, and specifically senile dementia of the Alzheimer's type. We see low levels of vitamin D correlating to other issues like Parkinson's, coronary artery disease, diabetes, and even autism. Now, why might there be this relationship between vitamin D and risk for Alzheimer's and dementia in general? Well, the researchers indicated that the clearance of this toxic beta amyloid by— is reduced when there's low levels of vitamin D, that vitamin D is necessary for activating those specific type of cells called macrophages that are able to digest away beta amyloid. It's also noted that the self-destruction of brain cells, a process called apoptosis, is actually increased when there's low levels of vitamin D, and the authors also stated that vitamin D deficiency has also been linked to vascular dysfunction, meaning blood supply problem, and ischemic stroke, or stroke caused by lack of blood supply. One thing that the authors of this study did not comment on, but I think is really quite relevant, and I'll tell you why in a moment, Is the role of vitamin D in activating something called cathelicidin. What is that? Cathelicidin is what we call an antimicrobial peptide. It's a peptide in the body, in the brain, that functions to get rid of microbes. This is how our brain tends to clean itself if it's exposed to certain microbes. And vitamin D activates that cathelicidin, that antimicrobial peptide. That's really important to think about these days when just about every week a new organism is identified, identified that may be related to cause of Alzheimer's. Recently, a dental organism was identified, Pyramonas digivalis. People thought that is the cause of Alzheimer's. Other organisms are likely related as well, certain types of herpes virus, And even chlamydia pneumoniae for that matter. But the point is, the brain is able to, to clear itself of these potential pathogens using things like this antimicrobial peptide called cathelicidin, which requires adequate amounts of vitamin D for its activation. So the point is that vitamin D really is important for the brain. It's good to have your blood level checked. and supplementing with a good vitamin D3 may well be in your interest. Thanks for listening. I'm Dr. David Perlmutter. Bye for now.
