The conversation around Vitamin D is complex and there are lots of myths and counter-claims passed around like cookies. Most are hearsay, old-wives-tales and the like, even if there may be grains of truth behind some of them. A recent series from Grassroots Health looks at the misinformation and, scientifically, discusses the reality. It’s an interesting story and, if you’re serious about your health, take some time to read through the different articles.
My takeaway from this is that you should be informed about the choices and not blindly supplement just for the sake of it. Although this will have some benefits in most cases, it might not have the optimum results without nutritional consultation or some form of periodic testing to ensure you tailor your supplementation for your specific needs. You can order these tests online (e.g. Thriva, Cerascreen, et al), but I would recommend getting professional advice on the results and your course of action to achieve the best results. (I have no affiliation with these companies and found them on a web search – do your own research first as I make no claims about the efficacy of these services).
Myth #1: Vitamin D is Stored in Fat for Use
While it is true that vitamin D, as a fat soluble vitamin, has a higher affinity for fat cells in the body, it is not stored as a means of maintaining a steady serum level necessary for health, which experts agree should be in the range of 40-60 ng/ml (100-150 nmol/L). In fact, the more fat a person has on their body, the more likely they are to have vitamin D deficiency.
Myth #2: Vitamin D is Toxic
Vitamin D build-up in body fat does not continue indefinitely. When there is a continuous supply of vitamin D, a balance is reached between the vitamin D stored within our body fat and its removal for use into the bloodstream.
Vitamin D toxicity is rare and usually caused by excessive vitamin D supplementation, which can lead to hypercalcemia (increased calcium in the blood), hyperphosphatemia (increased phosphate in the blood), and suppressed serum PTH concentrations. However, the vast majority of the population will not reach a vitamin D level of 40-60 ng/ml, the range recommended by the GrassrootsHealth panel of 48 vitamin D researchers and scientists, if taking only the daily recommended amount of 600 IU/day. Looking at a starting serum level of 20 ng/ml (close to the population average), an intake of at least 3,300 IU/day would be sufficient for only 50% of adults to achieve a level of 40 ng/ml or greater. Some will require more.
Myth #3: Taking Vitamin D Makes Other Nutrients Deficient
There is concern that taking “too much” vitamin D, especially when taken without co-nutrients, may create imbalances in the body – and this is a very valid concern! However, the reality is not so much that taking vitamin D causes another nutrient to become deficient, but that other pre-existing nutrient deficiencies may become more apparent when vitamin D is no longer the limiting nutrient in short supply.
Myth #4: Current Recommendations are Enough
A paper from Paul J. Veugelers, Ph.D. showed, through statistical analysis, using the same data the Institute of Medicine (IOM, now the National Academy of Medicine) chose to use to compute the RDA, that the correct analysis should have revealed an RDA closer to 8,895 IU/day. Both Veugelers, using the IOM data set, and Dr. Robert Heaney, using a separate data set from GrassrootsHealth, came up with approximately the same result, demonstrating that we need roughly 10 times more than the current recommendation.
Myth #5: Vitamin D Testing is Unnecessary
Having read the previous articles, it can be seen that supplementation alone does not guarantee an increase in Vitamin D serum levels in the body. Not only does the type of supplement have an effect, but also the body’s own chemistry and the level of other minerals present has an effect on uptake. The types of food you eat, plus sun exposure also contribute, as can skin type. Apparently redheads generate more Vitamin D with less sun exposure due to their genetic make-up.
Myth #6: Sun and Food Provide Enough Vitamin D
It takes more than exposing just the face, arms and legs for only 10-15 minutes per day for most people, and many may not be able get enough exposure simply due to other factors such as skin type, burning threshold, latitude, cloud cover, and time availability. For example, results from a study published in 2018 showed that Caucasians living in the UK needed nine minutes of mid-day sun with arms and legs exposed each day from March to September to maintain a vitamin D level at or above 10 ng/ml (25 nmol/L) year-round, which is significantly below the optimal range for health.
Myth #7: Kidney Stones
Some doctors think that because vitamin D helps the body to absorb calcium, higher intake of vitamin D can lead to kidney stones made of calcium. But there is something missing about this claim: evidence. Simply put, results from dozens of well-designed studies provide no evidence that vitamin D contributes to kidney stone formation. Two more recent case-controlled studies have shown that people with low levels of vitamin D are more than twice as likely to develop a kidney stone.
Myth #8: Vitamin D Supplementation Never has Side-Effects
While it is true that the majority of individuals have no issues when taking vitamin D (in fact, many notice improvements in how they feel), there is a very small percentage of people who do experience unwanted side-effects.
Myth #9: The Same Amount of Vitamin D is Good for Everyone
Everyone responds differently to vitamin D … by up to 6 times for the same supplement amount! Whether getting your vitamin D from sun or supplement, several factors can affect how much vitamin D is made, absorbed, or converted for use in the body. I touched on this under Myth 5 but this article goes deeper.
Myth #10: The Hormonal Vitamin D is the Only Form that Benefits Us
There is a common misconception that the only ‘active’ form of vitamin D, and the only one that really matters to our health, is the hormonal form 1,25- dihydroxyvitamin D [1,25(OH)2D], or calcitriol.