Vitamin D has been surrounded by controversy for years – with countless myths and half-truths circulating around it. Yet, our health depends on its levels: immune system, bones, muscles, mood, and even the risk of chronic diseases.
Thanks to GrassrootsHealth, a scientific organisation dedicated to studying the impact of vitamin D and sunlight on health, we take a closer look at the 6 most common myths – and explain what the science really says.
Vitamin D has long been a topic of great interest, as well as considerable controversy. On the one hand, it is praised for its essential role in immunity, bone and muscle health, and even mood regulation. On the other hand, numerous myths and misconceptions continue to circulate, often preventing people from recognising vitamin D as a vital component of overall health.
GrassrootsHealth, a scientific organisation dedicated to studying the impact of sunlight and vitamin D on the human body, has created the Vitamin D Myths series to dispel these common misunderstandings. On their website, you can find the full list of myths with explanations. In this article, we highlight the six most important ones that frequently appear in everyday discussions.
We encourage you to explore the additional GrassrootsHealth resources as well; they provide reliable, evidence-based knowledge to help you make informed decisions about your health and your vitamin D status.
Myth 1: You don’t need to supplement with vitamin D because it is stored in fat cells and the body can use it later.
Fact: Vitamin D is fat-soluble, but it is not stored in a way that maintains healthy blood levels, which is why we need regular intake. Moreover, the more body fat a person has, the greater their risk of vitamin D deficiency.
Myth 2: Vitamin D build-up in fat can be toxic.
Fact: Toxicity is rare! It may occur only at very high intakes, such as 50,000 IU per day or more for at least 6 months. Supplementation is considered safe; however, when taking higher doses it is important to regularly test vitamin D blood levels.
There is a very small group of individuals with rare conditions (such as primary hyperparathyroidism, sarcoidosis, or other granulomatous disorders) who should be especially cautious with vitamin D supplementation.
Myth 3: Taking vitamin D makes other nutrients deficient.
Fact: Vitamins and minerals in our body work together as co-nutrients. For vitamin D to be properly utilised, nutrients such as magnesium, zinc, copper, and selenium are essential. If any of them are lacking, metabolic processes can be limited.
For example, without sufficient magnesium, the body cannot fully convert vitamin D into its active forms. This is why, when supplementing with vitamin D, a pre-existing magnesium deficiency may become apparent, and it is often the real source of the problem.
In other words, vitamin D itself does not “drain” other nutrients from the body. Instead, deficiencies of co-nutrients can become more noticeable when vitamin D intake is increased. This is why it is important to maintain a varied diet and, if needed, consider additional supplementation with magnesium, vitamin K, or zinc.
Myth 4: Vitamin D testing is unnecessary.
Fact: Certain groups are at higher risk of deficiency – including people with darker skin, higher BMI, or older age. Many other factors also influence how each individual responds to vitamin D, which is why it is useful for everyone to test their levels.
Myth 5: Sun and a healthy diet are enough; supplementation is not necessary.
Fact: It is possible to get enough vitamin D from sun and food alone (for example, among native African tribes or people who work outdoors year-round), but for most people this is highly unlikely. Nearly everyone requires vitamin D supplementation to avoid deficiency.
Myth 6: Taking vitamin D causes kidney stones.
Fact: High levels of vitamin D do NOT cause kidney stones. Recent studies show that people with low vitamin D levels are more than twice as likely to develop kidney stones (see sources for more details)!
Vitamin D is only one piece of a bigger puzzle; a healthy lifestyle also includes balanced nutrition, exercise, sleep, and mindful exposure to sunlight. Remember: test your 25(OH)D level, enjoy sensible sun exposure, and support your body when it truly needs it.
You can find more facts and research on vitamin D at GrassrootsHealth, an international scientific organisation studying the impact of sunlight, vitamin D, and other nutrients on health. It is a reliable source of knowledge, testing, and practical tools to help you consciously take care of your vitamin D status. Check it out: grassrootshealth.net
Sources:
Blum M, Dolnikowski G, Seyoum E, Harris SS, Booth SL, Peterson J, Saltzman E, Dawson-Hughes B. Vitamin D(3) in fat tissue. Endocrine. 2008 Feb;33(1):90-4. doi: 10.1007/s12020-008-9051-4. Epub 2008 Mar 13. PMID: 18338271; PMCID: PMC2839878.
GrassrootsHealth: The Top Vitamin D Myths: What’s Fact and What’s Not?