According to the New York Times, "Millions of people are popping supplements in the belief that vitamin D can help turn back depression, fatigue, muscle weakness, even heart disease or cancer. In fact, there has never been widely accepted evidence that vitamin D is helpful in preventing or treating any of those conditions."
Vitamin D3 advocates always share the benefits, but they rarely talk about what can happen when you take too much. Vitamin D supplementation has a drastic effect on your mineral levels, namely calcium, potassium and boron which drastically alters your metabolic rate. Unfortunately this is something that is rarely talked about or acknowledged.
Yet it's taken daily in vitamin D supplements, multivitamins, and other combination supplements. Often it's taken in multiple different supplements at the same time, something I call "supplement stacking."
Just like all other dietary trends, the truth surfaces eventually... and surprise-surprise that truth is that a pill or supplement is NEVER the cure-all you're led to believe. If low vitamin D doesn't mean you just need to supplement vitamin D, what does it mean?
What low vitamin D can REALLY reveal
It appears that low vitamin D levels are the result of ill-health, but not the cause. Low vitamin D levels can reveal a host of things:
- Ill-health: According to a recent study done in December 2013 in Lancet Diabetes & Endocrinology, "The discrepancy between observational and interventional studies suggests that low 25(OH)D is a marker of ill health."
Additionally, a 2014 study looked at the link between inflammation as a cause of low vitamin D, "Despite increased supplementation chronic inflammatory diseases are on the rise. Attention to the alternate hypothesis—low 25(OH)D is a consequence of the chronic disease process, provoked by persistent intracellular infection—may be crucial to reversing this trend and needs further research. The prevailing dogma that the level of serum 25(OH)D provides an accurate assessment of vitamin D status needs closer examination. Circulating levels of 25(OH)D may not be an accurate reflection of vitamin D status. In those with an autoimmune disease or chronic inflammatory symptoms, 1,25(OH)2D may be elevated."[6, 11]
- Low calcium intake: Chris Masterjohn explains that vitamin D levels and calcium levels go hand in hand. "Overall, then, we would expect that a deficiency in calcium would cause low 25(OH)D, and that correcting the deficiency would normalize the 25(OH)D, but that beyond a certain threshold, increasing calcium intake might not increase 25(OH)D any further."  Additionally, he adds, "As a rule of thumb, then, I would say that if someone has low 25(OH)D and she is eating two to three servings of dairy products or soft, edible bones, or two to three cups of cruciferous vegetables per day (which have their downsides), then calcium deficiency is unlikely to be the explanation. If one is not eating these foods, however, it could very easily be the explanation. In such a case, the person has little to lose and much to gain by including more calcium-rich foods." 
- Poor digestion: Low vitamin D status can also be a reflector of poor gut health, especially since proper digestion is a precursor to good health. You can't be healthy without good digestion to make nutrients available and absorbable by the body. Digestion is king when it comes to health, and there are a host of reasons why people have poor digestion. The ones I see most frequently are due to a slowed metabolism, low nutrient diet, and chronic stress.
- Low magnesium intake: "Intake of magnesium significantly interacted with intake of vitamin D in relation to risk of both vitamin D deficiency and insufficiency."  And "Magnesium deficiency shuts down the vitamin D synthesis and metabolism pathway." As well as, "A randomized trial indicates that magnesium optimizes vitamin D status, raising it in people with deficient levels and lowering it in people with high levels." 
- Glyphosate (ie. Roundup, GMOs, non-organic food): This herbicide disrupts the key class of liver Cyp enzymes that are key for detoxifying chemicals as well as essential for activating vitamin D. Meaning, it could be vitamin D levels are low because the liver can’t activate the vitamin D because of how the glyphosate is disrupting the enzymes that are essential to the process. 
- Malnourished liver: Liver health plays a role in the absorption of vitamin D, because it affects both the production and flow of bile. Bile emulsifies fat (vitamin D is a fat soluble vitamin), and makes it more available for absorption in the gut.
- Boron deficiency: the mineral boron beneficially impacts the body’s use of estrogen, testosterone, and vitamin D 
- Vitamin C deficiency: vitamin D deficiency is less likely when one has optimal levels of vitamin C 
Vitamin D supplements - a magic bullet that may not be so magic?
As you may see, taking a vitamin D can sometimes be a distraction because it does not address the root cause of low vitamin D levels; a host of other issues contributing to ill-health.
However you slice it, vitamin D is still a hormone, and supplementation should be done carefully after proper testing since overdosing does pose risks.
According to Chris Masterjohn, "Vitamin D can be a double-edged sword: adequate vitamin D prevents heart disease, but too much vitamin D promotes heart disease. The available evidence suggests that the lowest risk of heart disease occurs when vitamin D status is between 20 and 40 ng/mL." 
Vitamin D Supplement Side Effects
Two major side effects of vitamin D is that it raises your calcium levels while driving down potassium levels. The impact of this on how you feel is highly significant. It can literally make your metabolic rate slower, since according to the fundamentals of hair analysis, the calcium to potassium ratio shows how well your thyroid hormones are doing their job. This is a pattern that I see with about 90% of my hair analysis clients who take high dose vitamin D supplements regularly.
Naturopathic Doctor Garret Smith warns, "Taking calcium and/or Vitamin D will provide a push to absorb more calcium from the gut and also to raise calcium levels in the blood, this is what these nutrients do and makes sense. The question becomes, when that calcium goes up higher than desirable in the blood, how does the body compensate for it? I’m going to tell you that it transfers it into “savings accounts” to clear it from the blood that you really won’t like…calcium deposits in the joints (aka osteoarthritis), kidneys (stones), blood vessels (heart disease), and even the brain." 
Here are some more side effects you may want to be aware of as well...
- Excessive Vitamin D May Increase the Risk of Autism in Infants
- Vitamin D Can Be Immunosuppressive
- Hypercalcemia and Metastatic Calcification
- Vitamin D May Cause Brain Lesions in the Elderly
I always question supplement trends, especially anything marketed as a "cure-all" or "easy button."
Instead of taking the "easy" path of trying to resolve a vitamin D deficiency with vitamin D supplements, I'd rather address the root cause(s) of low vitamin D levels first: nutrition? gut health? vitamin or mineral status? poor sun exposure?
Sometimes just asking yourself, "why do I have low vitamin D levels" versus just buying a supplement enables you to look at the situation from a whole new angle and address important vitamin and mineral levels that impact vitamin D levels (hint: vitamin C, boron levels, magnesium levels).
These things would be totally ignored or missed if you just popped a supplement that you might not even need (why testing is so important).
That's where the true magic happens, when you learn to think about your body in a whole different way. Good nutrition isn't about just picking up a supplement, it's about diving deeper, understanding your body, and getting strategic with what your body needs.
Some vitamin D is good. More is not always better. Testing before taking high dosages is smart.
Want to see how your vitamin D supplementation is impacting your thyroid and mineral levels?
With a simple hair analysis test, you can discover if vitamin D supplements are having an ill-impact on your mineral levels, your metabolism and your health.
Read all about why else you'd want to cut off your hair for your health here or enter your email below to learn all about the best way to understand your own mineral levels with hair analysis.
Do you have low vitamin D levels? Please share in the comments what you think!
11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4160567/ add