The Weekly Thread: vitamin D supplementation & dementia, the doctor’s kitchen, and the 80/20 principle.

Does Vitamin D supplementation decrease risk of dementia?

I came across a prospective cohort study that examined the association between vitamin D supplementation and incident dementia in 12,388 dementia-free adults from the National Alzheimer's Coordinating Center titled, Vitamin D supplementation and incident dementia: Effects of sex, APOE, and baseline cognitive status, and published fairly recently in March 2023. 

Vitamin D is a nutrient that is essential for many bodily functions, including bone health, immune function, and cognitive function. In recent years, there has been growing interest in the potential role of vitamin D in dementia prevention, and this study aimed to see if there was a correlation between actual vitamin D supplementation and incidence of dementia. 

In short, the study found and stated that “vitamin D exposure was associated with significantly longer dementia-free survival and lower dementia incidence rate than no exposure”. 

SIGNIFICANTLY longer dementia-free survival and lower dementia incidence.

Here are some key highlights from the findings of this study:

  • Vitamin D exposure was associated with 40% lower dementia incidence versus no exposure.
  • Vitamin D effects were significantly greater in females versus males and in normal cognition versus mild cognitive impairment.
  • Vitamin D effects were significantly greater in apolipoprotein E ε4 non-carriers versus carriers.

Let’s unpack these findings a bit more. 

Overall, the occurrence of vitamin D supplementation showed a 40% lower incidence of dementia, which I would definitely agree, is quite significant, especially considering this is just a single, very inexpensive preventive intervention with a host of other researched potential benefits such as improved immune function, and reduced risk of other diseases. 

That said, the study found that women (who also comprise 65-70% of the total population afflicted with Alzheimer’s) were even more significantly affected by vitamin D supplementation.

It also found that those who exhibit no signs of dementia, and had normal cognitive function were also more significantly affected by vitamin D supplementation. Which means, prevention here with vitamin D supplementation (and natural sunlight exposure, which is the natural way to supplement with vitamin D3) is key, as supplementation BEFORE any signs of dementia actually shows a greater impact on helping to keep you free of dementia. 

Finally, non-carriers of APOE e4, a common genetic risk factor for Alzheimer’s, were found to also have a more significant impact on reducing incidence of dementia with vitamin D supplementation. (You can find this out with a basic genetic test) 


The study's findings are consistent with some previous research, which has suggested that vitamin D deficiency may be a risk factor for dementia. The difference with this study was that it was attempting to see if there was a correlation between actual vitamin D supplementation and incidence of dementia, which was found, and found to be significant at that. 

One limiting factor of the study was that it was observational and based on existing data sets, and was unable to determine a therapeutic, researched dose of vitamin D supplementation to reduce risk of incidence of dementia. 

Vitamin D supplementation needs can vary based on the individual, so it always helps to get your levels checked with some blood work. That said, there are some general rules I tend to follow that I think are pretty reliable. 

During the warmer spring and summer months, where sunlight is far more direct, and thus, effective at helping the body to naturally produce vitamin D3 (as well as making it more enjoyable to be outside gaining that natural exposure) I try to get as much natural light exposure as possible, and then supplement with probably 10,000-15,000iu of vitamin D3 per week. 

During the colder, drearier winter months, where sunlight is also far less direct, and far less effective at helping to produce D3 naturally, I will supplement with upwards of 50,000iu per week. 

I also recommend supplementing with extra vitamin K2 either through a high quality multivitamin, or a separate vitamin K2 supplement, with a vitamin D3 supplement. 

Vitamin D3 when taken in higher, what would be known as “therapeutic doses”, helps with calcium absorption, which is great for your bones, however, it can also lead to calcium buildup in your bloodstream, which you don’t want, and vitamin K2 helps mitigate that, along with having its own therapeutic benefits. 

This is a relatively minor downside to vitamin D3 supplementation, which can easily be offset by supplementing with extra vitamin K2, and I would say the tremendous, multi-faceted health benefits of supplementing with vitamin D3 far outweigh this minor downside. 

Last week, I discussed the mindset of “longevity”, and how it starts now, with small, incremental steps. Vitamin D3 supplementation is probably the most inexpensive supplement you can buy, making it a cost-effective, easy thing to implement on your quest for greater longevity. 

The Doctor’s Kitchen

I recently listened to a podcast with Dr. Ruby Aujla, who is the found of The Doctor’s Kitchen

In a time where everyone has a diet to sell you on, and they can get real dogmatic about it as well, most research points to consistency in healthy eating as the most important factor in losing weight, and maintaining a healthy body composition. 

Which means ultimately, whether it’s keto, vegetarian, carnivore, Mediterranean, Whole 30, or just following general, healthy eating principles, whatever it is, if it fits with you, the way you like to eat, and thus, you can be consistent with it, then that’s the right approach for you. 

For example, I have my own personal approach to eating healthy, which includes lots of animal-based protein and fat, copious amounts of olive oil, organic fruit, raw honey, and small amounts of sprouted nuts and seeds, and organic, biodynamic dark chocolate (yes, dark chocolate almost every day, as it really is that good for you). 

This is great for me, as I respond well to it from a performance and body composition perspective, however, I don’t think that means everyone should eat just like me, just because it works well for me, my energy levels, and my personal preferences. 

Dr. Aujla takes this more objective approach (which I found refreshing) to nutrition, and really just seems to be on a mission to educate individuals on how to eat the most nutrient-rich foods, for specific purposes, that fit into your lifestyle. 

The Doctor’s Kitchen has a mobile app that he plans to grow into an incredible resource where, say, down the road, you can enter certain parameters such as wanting to cook a meal with nutrients for brain health, where you can enter a budget, and it will recommend recipes and shopping lists based on that. Pretty cool stuff in the pipeline. 

Click below to check out the podcast I listened to on “The Genius Life Podcast” titled, “The Top Foods to eat for Weight Loss and Balanced Blood Sugar”. 

CLCK HERE to listen on Apple.

CLICK HERE to listen on Spotify. 

The 80/20 principle, also known as the Pareto principle, states that roughly 80% of results come from 20% of efforts or causes. It's a concept often used to highlight the unequal distribution of outcomes, where a small portion of inputs or actions usually generates the majority of desired outcomes.

When actively applied, it makes you more efficient at pretty much everything in your life. 

How you spend your time.

Who you spend your time with. 

What you place real value on. 

I myself, am trying to consciously, and more actively apply the 80/20 principle in various areas of my life, and as I think about certain areas more deeply, I’ll share them with you here. 

I found this to be a simple, effective exercise to get started:

On a sheet of paper, list the 5 people you spend the most time with. (Exclude people you may be forced to spend time with for long periods, such as co-workers)

Basically, write down the 5 people you spend the most amount of (discretionary) time with. 

Now, on the same or separate sheet of paper, list the 5 people in your life that you want to spend the most (discretionary) time with. These are the 5 people you get the most value out of spending time with. The 5 people who most enrich your life and overall existence. 

Now, compare the two lists. 

Do they closely align, or are they not so similar?

On the latter of the two lists, you’ve gone and identified the people in your life who fit the 80/20 principle. Spending discretionary time with them yields the most impact on your life, well-being, et cetera, and thus, are the people most worthy of your very precious discretionary time. And most likely, if there is reciprocity in the dynamic, you for them.

If they don’t align, maybe it’s worth thinking more deeply about how you can reconnect or spend more time with the people you yourself have just deemed the most impactful, highest value people in your life.