Minerals & Trace Elements

Iron as a Nutrient: Oral vs IV Replacement

Iron is the atom oxygen rides on. Without it, haemoglobin cannot carry a breath from lung to tissue, and the commonest nutritional deficiency on earth quietly sets in. Replacing it looks trivial — a cheap tablet on a pharmacy shelf — yet it is one of the most botched prescriptions in medicine. Half of patients quietly stop the pills because of the churning gut they cause, others are given iron they never needed, and a few are handed an intravenous infusion when a tablet would have done. Getting iron right is a lesson in absorption physiology: who can take up the mineral, what blocks it, and when to bypass the gut altogether.

Trace Elements: Zinc, Copper, Selenium and the Rest

You need them in milligrams — sometimes micrograms — a day, and yet an enzyme somewhere will not turn over without them. Trace elements are the tiny metal cofactors threaded through hundreds of reactions: the zinc in a healing wound, the copper that lets you use iron, the selenium guarding a heart muscle from oxidative damage. Run short and the body writes a distinctive signature — a rash around the mouth, an anaemia that looks like marrow failure, a cardiomyopathy in a starving child. And two of them, zinc and copper, are locked in a see-saw so tight that treating one deficiency can quietly cause the other. This is the chapter of small amounts and sharp consequences.

Iodine: The Thyroid's Raw Material and Its Paradoxes

Most trace elements do a dozen quiet jobs scattered across the body. Iodine does exactly one thing, and does it nowhere but the thyroid: it is the raw material of thyroid hormone. That single-mindedness makes it the most elegant mineral in pharmacology — because a substance with one job has one organ to break, and it can break it in opposite directions. Too little iodine and the thyroid starves; too much and it can either shut down or run wild. The dose and the timing decide which. Nowhere else does a nutrient behave so much like a drug.

Dietary Supplements: Overdose, Interactions and What Actually Works

Half your patients are taking something you didn't prescribe — a multivitamin, a fish-oil capsule, a herbal remedy a friend swore by. They don't think of it as medicine, so they don't mention it, and you don't ask. That is a mistake. A supplement is a drug: it has a dose, it has adverse effects, and it interacts with the very medicines you carefully chose. Most of them do nothing measurable in a well-nourished person. A few genuinely save lives when there is a real deficiency. And a handful — St John's wort at the top of the list — can quietly wreck a treatment plan. The skill is telling the three apart.