This Vitamin D Mistake Is Making You Sicker (Do This Instead)

You take vitamin D every day, but if you're making this mistake, not only is it not helping you, it may actually make you sicker. Most people think of vitamin D as harmless, just a simple supplement for your bones, or your mood, or your immune system. But here's the thing, if you take it the wrong way, your blood levels may just never rise, or you may get vitamin D toxicity, which can lead to kidney stones, and heart issues, and even neuropsychiatric changes. So let's talk about what actually happens in your body when you take vitamin D, and why the way you take it determines whether it helps you or quietly harms you. So first, vitamin D is fat soluble, which means your body can't just absorb it like vitamin C, or vitamin B, or those water-soluble vitamins. Vitamin D needs fat to get through your gut wall and into your bloodstream. Now here's where the first big mistake comes in. Most people take in the morning, or on an empty stomach with water or coffee. And if you're doing that, you might as well be throwing a lot of it away. And we have studies that show that people that take vitamin D with fat absorb 32% more than the fat-free group. So same dose, but a third more actually got into the body simply because of what they ate with it. And that brings up another problem. Let's say you are taking vitamin D with fat, but if you're not seeing a difference, well then you need to look into what kind of fat you're consuming, because that matters more than most people think. There was a study that was published by the Endocrine Society that showed that diets rich in monounsaturated fats improve effectiveness of vitamin D supplementations, while diets rich in polyunsaturated fats reduce that effectiveness. And this is not to say one type of fat is better than the other, or you should avoid polyunsaturated fats, because that's not the case. But if vitamin D absorption is what we're focusing on, the type of fat you take matters. So what's the big difference and what does it look like? Well, monounsaturated fats, this is the fat that can help with vitamin D absorption. The reason they're called monounsaturated is because their molecular structure has only one double bond, whereas polyunsaturated fats, poly means many, have more than one double bonds in their chemical structure. So that's what gives them different properties. So for monounsaturated fats, you'll get those from olive oil or sesame oil or avocados, whereas polyunsaturated fats, well, those would be your omega-3 or omega-6 fatty acids, which come from fatty fish and nuts and seeds and many plant-based oils. But I want to emphasize, this is not to say you need to avoid certain fats altogether, but we need to take your vitamin with the correct fat to maximize that absorption. Okay, another hidden issue is even if you do absorb vitamin D well, your body may not actually use it without two other key nutrients. And the first one is magnesium. And magnesium is important because vitamin D is biologically inactive until it becomes activated or it's converted into its active form in the liver and the kidneys. And both of those steps require magnesium. And without magnesium, your vitamin D may just sit there unused. So that's why people can take thousands of international units of vitamin D per day and still not see their levels budge, because what they're really deficient in is magnesium. And this is an incredibly important point, because if you pair high-dose vitamin D while your magnesium stores are low, you may actually hurt yourself in the process, because this is what accelerates calcium buildup. And there are studies like this randomized control trial that showed that combining vitamin D with 360 milligrams of magnesium glycinate for 12 weeks was more effective in increasing serum 25 hydroxy vitamin D levels compared to vitamin D supplementation alone. So the take-home message here is your vitamin D supplements will not work without adequate magnesium stores. And that's concerning, because it's estimated that about half of the U.S. population does not get enough magnesium. Now, let's talk about another nutrient that people often tell you to pair with your vitamin D, and that is vitamin K2. And this is where it gets a little controversial. So the argument for K2 with vitamin D is you need vitamin K2 to help direct all that extra calcium you absorb with vitamin D into the bones as opposed to your blood vessels. But does the current evidence actually support this claim? Well, the short answer is maybe. There's enough evidence to say that vitamin K2 does support bone health. And the best study for this was this three-year randomized control trial from 2013 that showed that taking 180 micrograms of vitamin K2 in the form of menaquinone-7 or MK-7 significantly reduced bone loss, especially in the lumbar spine and the femoral neck around the hip. And a recent meta-analysis of 16 randomized control trials did seem to indicate that vitamin K2 supplementation can indirectly promote bone mineralization, and it increases bone strength. So yes, clinically, it does seem that vitamin K2, especially MK-7, can help with bone density and it can lower fracture risk if we can extrapolate those results from postmenopausal women to the general population. But what about unopposed vitamin D without vitamin K calcifying your blood vessels? Or does vitamin K actually help with your heart health? Well, this is where the evidence gets kind of shaky, and it's not that strong. There was a pretty good study published in Circulation in 2022 that was a randomized double-blind clinical trial that showed that older men with calcified aortic valves taking vitamin K with vitamin D for two years did not have any effect on the progression of their calcification. So they did not see any difference there. Okay, so that's heart valves, but what about blood vessels? Well, there was another randomized control trial in 2023 that randomized participants to taking 720 micrograms of K2 with vitamin D, and they measured their coronary artery calcium scores. And after two years, they found no significant difference between the placebo group and the K2 plus vitamin D group. So no difference there as well. But one caveat though, they did a subgroup analysis in the study, and in the really high-risk group, so the participants whose baseline calcium score was greater than 400, they did see a slower progression of calcification. So there may be a signal of benefit in the really high-risk groups for heart disease, but we would need a much larger study to see if it was just a signal or an actual statistically significant benefit. Oh, by the way, probably the most studied version of vitamin K2 in a lot of these studies was MK7. So that's the version I recommend to my patients when it comes to bone strength. And when it comes to heart health, I don't usually go out of my way and personally recommend K2 specifically for the heart, as at this juncture, the evidence is just not there yet. But I wouldn't recommend against it if someone was concerned about taking vitamin D and worsening of their coronary disease. Because for the most part, it's a pretty benign intervention, and unless someone has clotting problems or requires to be on a blood thinner like warfarin or coumadin, vitamin K2 under doctor's supervision should be very safe. Okay, another mistake that I see all the time when it comes to vitamin D is taking too much. And I see recommendations out there taking 5,000, 10,000, or whopping doses of vitamin D every day. But even though vitamin D is incredibly important for our overall health, more is not always better. And there's randomized control trials that have shown that high doses of vitamin D resulted in an increased risk of falls and fractures. And there's also increased risk of kidney stones if excess vitamin D is taken with And a recent systematic review and meta-analysis show that doses as low as 3,200 to 4,000 international units per day appear to increase the risk of hypercalcemia or having too much calcium and other adverse events. And those adverse events are still pretty rare, but they can be very serious. So bottom line is, if you're taking vitamin D, especially at doses higher than 3,000 to 4,000 IUs per day, you need to periodically check your vitamin D and calcium levels to make sure you're not overdosing it, or you're actually increasing your levels. And talk to your doctor about what your optimal vitamin D levels should be, as those targets can be different from person to person. All right, I hope this was helpful. Stay healthy, and I'll see you in the next one.