Echinacea, vitamin C and zinc gummies

Every autumn the same three names appear together on the front of a jar: echinacea, vitamin C and zinc. The combination is marketed as immune support, and in gummy form it is aimed at people who will not take three separate tablets.

What each part is there for

Vitamin C contributes to normal immune function and is the least controversial of the three. Zinc plays a role in immune function too and is the one most often linked with the length of a cold. Echinacea is the herbal element, used traditionally at the first sign of a cold, with evidence that has stayed mixed for a long time.

Put together, the blend covers a familiar idea rather than a proven formula.

What a blend hides

Convenience costs clarity. In a combined product you cannot easily tell how much of each ingredient you are getting, whether the zinc is in a well absorbed form, or which part of the mixture disagrees with you if something does. Serving sizes vary widely between brands, and so does the sugar that carries the flavour.

If you already take a multivitamin, a cold-season blend may repeat what is in it. Reading both labels together is the only way to know.

Who should check first

Zinc interacts with some antibiotics and, taken heavily over a long stretch, interferes with copper. Echinacea is a plant of the daisy family, so anyone with related allergies should be careful, and it is usually avoided in pregnancy and by people on medicines that affect the immune system.

A pharmacist can rule these in or out quickly, which is the point of asking rather than guessing.

What still works better

Sleep, hand washing, ventilation and a diet with fruit and vegetables in it do more against a winter of colds than any jar does. A supplement sits on top of those; it does not replace them.

Taken with modest expectations, an immune gummy is a harmless seasonal habit for most adults. Taken as insurance against ever catching anything, it will disappoint.