By Garba “MisterG” Onadja | Calabasas Top Trainer
When I coach someone toward better performance and longevity, I look for habits that produce results. A supplement may sound promising, but the real question is what happens when people take it.
A recent article in The Economist, “Consuming extra vitamin D is less good than it sounds,” raises exactly that question. It prompted me to look at what the evidence means for the people I coach.
Your body needs vitamin D
Vitamin D helps the body absorb calcium and maintain healthy bones. Too little can cause serious problems. There is no debate about the need for an adequate amount; the debate is whether taking extra vitamin D gives an otherwise healthy person additional protection.
That idea attracted attention for good reason. Researchers observed links between low vitamin D levels and a range of health problems. But a link does not tell us whether a supplement will prevent those problems. Large trials have given us a way to test the promise. For generally healthy adults, the results have been less impressive than the theory: supplemental vitamin D did not significantly reduce fractures in a major trial, and current guidance does not recommend routinely taking more than the recommended daily intake to prevent disease in healthy adults under 75.
My take as a coach
I would not sell vitamin D as a shortcut to stronger muscles, better balance, or a longer life. In training, I see progress come from consistent work: building strength, practicing balance, moving with control, eating well, and recovering. A supplement has a role when someone needs it, but it cannot do that work for them.
The details of your health matter. The Endocrine Society’s guidance identifies some groups who may benefit from supplementation, including adults 75 and older and adults with high-risk prediabetes. Someone with a diagnosed deficiency or another medical reason for treatment needs advice tailored to that situation. This is why “everyone should take it” and “no one needs it” are both too simple.
If you are considering a supplement, review your diet, any supplements you already take, and your health history with your clinician. More is not automatically safer: excessive vitamin D from supplements can be harmful.
My guiding principle is simple: give your body what it needs, then put your energy into the practices you can sustain. That is how we build strength for the years ahead.
Article inspiration and credit: This commentary was inspired by The Economist’s “Consuming extra vitamin D is less good than it sounds” (September 18, 2026). The coaching perspective and wording here are original. Medical guidance was checked against the Endocrine Society’s vitamin D guideline and the NIH Office of Dietary Supplements vitamin D fact sheet.