The vitamins your body actually needs in winter

Supplement aisles get busier every winter, but most people only need to think about two or three nutrients — the rest is marketing.

Vitamin D tops the list for anyone getting less sunlight in colder months. A simple blood test can tell you whether supplementation is actually necessary rather than guessing.

Vitamin C supports immune function, but the effect is modest for most people who already eat citrus fruits or vegetables regularly — it's not a substitute for rest when you're already sick.

Iron deficiency is worth ruling out if you're feeling unusually fatigued through winter, particularly for anyone with heavy menstrual cycles or a mostly plant-based diet.

Before starting any supplement routine, a quick conversation with a doctor is more useful than trial and error — some vitamins interact with existing medications or conditions.