Vitamins
Vitamin D: A Summary for You
Why adequate vitamin D status is essential from autumn onward and how to reach optimal levels—a scientific overview.
Vitamins
Why adequate vitamin D status is essential from autumn onward and how to reach optimal levels—a scientific overview.
Line items
Every year we're reminded that good vitamin D status from now on—that is, from autumn onward—can only be assured through supplementation. Anyone who values their health and staying healthy should simply be aware of this.
The reason is straightforward:
Your body converts vitamin D into a hormone called calcitriol. A hormone. Like testosterone and so on. Calcitriol regulates about 1,000 genes, and many of them play key roles in immune function. What many don't realize is that immune cells—like macrophages—that detect bacterial infections convert circulating vitamin D into calcitriol. The calcitriol produced this way then triggers the formation of antibacterial proteins, such as cathelicidin. Basic biochemistry.
An important study shows that in Switzerland too, a large share of the population doesn't reach normal vitamin D status in winter. Bear in mind: we're talking about values of 50 nmol/L or above, that is 20 ng/ml. Values of 75 nmol/L and above are considered optimal, which aligns with the recommendation of the Endocrine Society (and some other professional organizations). Fewer people achieve this.
Why do we need more reasons? Yet every year anew, articles in the "trade press" tell us the opposite. Sometimes we're told that "most people don't have a deficiency anyway"—hence the wise advice: "When in doubt, just don't take anything."
Fortunately, more and more articles are being corrected, showing that "some cited studies were not adequately contextualized or were misinterpreted." The overall tone, however, remains the same. Puzzling, given that vitamin D might be the safest vitamin there is—because in summer your body produces amounts that most of us would never consume with a standard pharmacy dose anyway.
Medical science continues to publish prolifically on the basis of measurements and calculations, and publishes in the best, truly peer-reviewed journals (like Nature) summaries of findings from many gold-standard studies, with the result:
"To achieve an adequate vitamin D concentration (75 nmol/L) in the blood, the recommended vitamin D intake is 1,340 and 2,250 IU/day for children and pregnant women, and 2,519 and 797 IU/day for European adults ages 18–64 and 65–85 years (…)"
So they recommend 75 nmol/L directly—not 50, as some authorities suggest. And here's something in black and white that's often overlooked in the media: adults need well over 2,000 IU of vitamin D per day. An "outrageous" amount that some authorities dismiss as "dangerous" and "unnecessary for the general population."
Here we see a huge discrepancy again—one might say, a cognitive dissonance. For surely even the responsible authorities should realize that practically everyone has a vitamin D deficiency in winter, and that normal levels (50 nmol/L = 20 ng/ml), or better yet, optimal levels (75 nmol/L = 30 ng/ml), can only be achieved with daily amounts well above the "permitted" 800 IU.
This brings us to another point entirely—a societal one. Why does anxiety seem more pronounced in some cultures? Might this be due to chronic vitamin D deficiency? The darkest, most severe winter blues in the dark months? Scandinavians have their vitamin D-rich fish, at least—what do inhabitants of more northern regions have as a natural vitamin D source?
Be that as it may: the well-known Dr. Rhonda Patrick published in 2014 and in 2015 two research articles together with Bruce Ames, arguably the most renowned biochemist of our time, demonstrating that calcitriol (active vitamin D) activates the serotonin-producing enzyme TPH2 in the brain. Adequate vitamin D in your body means adequate serotonin in your brain. A quick reminder: serotonin is the neurotransmitter people call the "happiness hormone," and it's in short supply in winter.
The circle closes.
