Why does my body need just a pinch of vitamins?

Think about your dinner plate: a heap of rice, a spoon of beans, and a carrot that crunches loudly when you bite it. Your body takes in big spoonfuls of food every day. Yet all the vitamins you need in one day would fit in a pinch between your fingers.

Food comes in heaps, but vitamins come in crumbs. So why does your body need just a pinch of vitamins, when it eats so much of everything else?

Most of your food gets used up. Your body burns some of it as fuel, and that fuel gives you energy to run and jump. It turns other bits into new bone and muscle as you grow. Once your body uses those bits, they are gone, so it needs lots more food every day.

All day and all night, jobs go on inside you, like turning food into energy and growing new skin over a scraped knee. Your body does these jobs with enzymes, tiny workers inside you that each do one special job.

Many enzymes cannot do their job alone. They need a small helper that clicks into them, the way a key fits into a lock. Many vitamins are these helpers, and with a vitamin in place, the enzyme can get to work.

Picture one enzyme with its vitamin helper clicked in, turning a crumb of food into energy for your legs. Snap, the job is done in a blink. Now what do you think happens to the little vitamin helper?

The vitamin helper is not used up like fuel. It slips free, and then the same enzyme or another one catches it for the next job. One helper can do this again and again, many, many times.

That is why your body needs only a pinch: a few helpers can keep job after job going. Bit by bit, some helpers wear out or leave your body. Fruit, vegetables and other good food bring fresh ones in each day.

One word to remember: enzymes. Your body needs just a pinch of vitamins because its enzymes use each vitamin helper again and again, so a few helpers do lots of jobs.

Sleep well tonight, while your tiny workers and their helpers keep busy inside you.