9 guides
Micronutrients
Vitamins and minerals: intake guidelines, deficiency signs, timing, and how nutrients compete with each other.
Tests and markers
Conditions and symptoms
The B12 Deficiency Signs That Get Missed Most Often
Search this phrase and you get a list built around tiredness. The signs that actually get overlooked are neurological, and the uncomfortable part is that they can show up before a standard blood count flags anything at all.
Moderate evidence18 Sept 2026
Why Are Potassium Supplements Capped at 99 mg Over the Counter?
The number on the label reads like a safety verdict — as if anything more would be dangerous. It is closer to a paperwork line drawn in the 1970s, and it has almost nothing to do with how much potassium an adult actually needs.
Strong evidence18 Sept 2026
Nutrients
Folate vs. Folic Acid: Are They Actually the Same Thing?
Every label and most articles file these under one word: vitamin B9. The chemistry underneath doesn't treat them as one thing, and the gap between them is exactly why pregnancy guidance names one by name and why only one of them has an official upper limit.
Strong evidence18 Sept 2026
How Much Vitamin D Should You Actually Take Every Day?
The RDA is 600 to 800 IU a day. The bottle on the pharmacy shelf says 2,000, or 5,000, or more. Both figures are real — one is a target, the other is a ceiling, and mixing them up is where most of the worry starts.
Moderate evidence18 Sept 2026
Explainers
Do Calcium Supplements Actually Raise Your Risk of Arterial Plaque?
One well-known set of clinical trials tied calcium pills to more heart attacks, not fewer. The largest study to separate diet from supplements found the signal sitting specifically with the pill and not with the food — which is the real question here, not whether calcium is broadly "good" or "bad."
Contested18 Sept 2026
Does It Matter What Time of Day You Take Magnesium?
Supplement labels split into two camps: some say timing makes no difference, others say take it at night for sleep. Both are answering a narrower question than the one on the bottle, and neither is really about when your body absorbs magnesium best.
Limited evidence18 Sept 2026
Why Do Iron Supplements Cause Constipation, and What Actually Helps?
Constipation sits on every list of iron supplement side effects like a minor footnote. The dose, the chemical form and the timing of the pill are what actually decide how much of it you get — and most advice online gets exactly one of the three right.
Moderate evidence18 Sept 2026
Why Long-Term Zinc Use Can Deplete Your Copper (and What to Watch For)
Every zinc bottle mentions copper somewhere in the fine print, usually without saying at what dose the two actually start competing, or what it looks like when copper loses.
Moderate evidence18 Sept 2026