Vitamin D and Insulin Resistance: What You Need to Know
Vitamin D has become one of the most talked-about nutrients in the last decade, and for good reason. It plays a crucial role in immune function, bone health, hormone regulation, mood stability, and even insulin sensitivity. Low levels of vitamin D have been linked to a higher risk of chronic illnesses, including heart disease, autoimmune conditions, and even certain cancers. Naturally, when widespread vitamin D deficiency was discovered, the response was simple—everyone should start taking more vitamin D supplements.
But let’s take a step back. If so many people are deficient, is the real problem just a lack of supplementation, or is there something deeper going on?
What’s Causing the Widespread Vitamin D Deficiency?
Most of the discussion around vitamin D focuses on inadequate sun exposure and dietary intake. While these are factors, they don’t explain why even people who get plenty of sunlight and take high doses of supplements still struggle with low levels.
One of the biggest, yet often overlooked, causes of vitamin D deficiency is insulin resistance.
When you have insulin resistance, it causes you store more fat. Those fat cells absorb and store vitamin D instead of making it available in circulation. Since vitamin D is a fat-soluble vitamin, it naturally gets stored in fat tissue. The more insulin-resistant someone is, the more fat they tend to store, and the more vitamin D gets “trapped” in their fat cells. This means that when you get a blood test, your vitamin D levels appear low—not because your body isn’t getting enough, but because it’s not in the blood.
This is why some people take high doses of vitamin D supplements and still see little to no improvement in their levels or symptoms. They aren’t fixing the reason their vitamin D levels are low in the first place.
Vitamin D and Insulin Resistance: The Missing Link
Studies have shown that vitamin D plays a role in improving insulin sensitivity, but just like with magnesium, this is a two-way street. Low vitamin D is linked to insulin resistance, but insulin resistance itself is also causing low vitamin D.
So if you look at all the diseases vitamin D deficiency is linked to, it begs the question—is vitamin D deficiency actually causing these problems, or are people with low vitamin D often insulin resistant, and insulin resistance itself is the real issue?
We know insulin resistance is linked to heart disease, inflammation, cognitive decline, weakened immune function, infertility, and more. So are the health conditions we associate with vitamin D deficiency actually being driven by insulin resistance instead? Correlation doesn’t equal causation, and just because vitamin D levels are low in these conditions doesn’t mean that taking more vitamin D is the solution.
The body’s inability to regulate vitamin D properly is yet another consequence of a dysfunctional metabolism. Instead of just reaching for the most expensive vitamin D supplement on the market, the smarter approach is to focus on lowering insulin levels and improving metabolic health. By doing this, your body can start naturally releasing and utilizing the vitamin D it already has, rather than keeping it locked away in fat stores.
Should You Supplement with Vitamin D?
If your vitamin D levels are low, supplementation may help, but it shouldn’t be your only strategy. Before assuming that taking more is the solution, focus on the root cause—insulin resistance. When insulin levels come down, vitamin D is better utilized by the body, and supplementation may not even be necessary.
Instead of obsessing over high-dose vitamin D pills, prioritize:
- A Lpw Insulin Lifestyle to improve metabolic function
- Daily movement to support insulin sensitivity
- Getting sunlight, as natural vitamin D synthesis is so important
Vitamin D deficiency is real, but the way we approach it has been overly simplistic. Before adding another supplement to your routine, step back and look at the why behind the deficiency. Fixing insulin resistance not only helps vitamin D levels stabilize but improves overall health in ways that supplementation alone never could.
References
Carrelli A, et al. Vitamin D Storage in Adipose Tissue of Obese and Normal Weight Women. J Bone Miner Res. 2017 Feb;32(2):237-242. doi: 10.1002/jbmr.2979. Epub 2016. Read more
Blum M, et al. Vitamin D(3) in fat tissue. Endocrine. 2008. Read more
