Too little — or too much — of a single vitamin or mineral can change how you feel. These guides explain what each one does, the signs of a deficiency, and how to read your levels the way a doctor does.
The Omega-3 Index is one of the most useful health tests you have probably never heard of. Millions of people swallow a fish-oil capsule every morning and simply hope it is doing something — with no way of knowing whether it actually is. This single blood test answers that question directly: it measures how much…
Vitamin E was, for a while, the vitamin that promised everything. As a powerful antioxidant, it was sold as protection against heart disease, cancer and even ageing itself — and millions reached for high-dose capsules on the strength of that promise. The reality, uncovered by large trials, turned out to be far more modest, and…
Vitamin A is a nutrient of contrasts. It gives you night vision, keeps your immune system sharp and helps your skin and cells renew — yet it is also one of the very few vitamins you can genuinely take too much of. Where a surplus of something like vitamin C simply washes away, vitamin A…
Vitamin C may be the most famous nutrient of all — the one people reach for at the first sniffle and pour into their morning orange juice. It is genuinely important: your body cannot make it, cannot store much of it, and needs a fresh supply every day to build skin, heal wounds and keep…
Vitamin K is the quiet workhorse behind one of your body’s most vital tricks: stopping bleeding. Named from the German word for clotting, Koagulation, it is the vitamin that lets your blood form a clot and seal a wound — and the same vitamin is increasingly recognised for helping keep your bones strong and your…
Iodine is one of the smallest entries on any nutrition label and one of the most important — because without it, your thyroid simply cannot make its hormones. This trace mineral has a single, non-negotiable job: it is the raw material your body builds thyroid hormones from, and those hormones set the pace of your…
Vitamin C is the supplement people reach for at the first sign of a sniffle — but does it actually work, and what else does it do? Vitamin C is a water-soluble vitamin your body can’t make or store, so you need a regular supply from food. It builds collagen, acts as an antioxidant, supports…
Vitamin A deficiency is rare in well-fed countries but remains a leading cause of preventable blindness worldwide — and vitamin A is unusual among vitamins because getting too much can be just as harmful as getting too little. This fat-soluble vitamin keeps your vision sharp in dim light, supports your immune system, and helps your…
Your sodium levels say less about how much salt you eat and more about your body’s water balance. Sodium is the main electrolyte in the fluid outside your cells, and your body guards its concentration within a narrow range — because where sodium goes, water follows. A reading that’s too high or too low is…
Selenium is a trace mineral your body needs in only tiny amounts, yet it quietly powers some of your most important systems — from your thyroid to your antioxidant defences. Because you need so little of it, selenium also has one of the narrowest safe windows of any nutrient: too little causes problems, and so…