They edit the genome of the red tomato to turn it into a solid source of vitamin D

London. If British scientists have their way, eating two medium red tomatoes a day could keep us from seeing the doctor.

A team, led by scientists at the John Innes Center in Norwich, edited the genetic makeup of red tomatoes to turn them into a robust source of vitamin D, which regulates nutrients such as calcium that are essential for maintaining healthy bones, teeth and muscles.

Although vitamin D is created in our bodies after exposure to sunlight, its main source is food, especially dairy and meat.

According to the researchers, low vitamin D levels associated with a host of conditions, from cancer to cardiovascular disease, affect an estimated one billion people worldwide.

Tomato leaves naturally contain one of the basic components of vitamin D3, called 7-DHC, considered the best for increasing D levels in the body.

The scientists used the Crispr tool – designed to work like a pair of genetic scissors – to modify the plant genome so that 7-DHC accumulates substantially in the fruit as well as in the leaves.

When the leaves and cut fruit were exposed to ultraviolet light for one hour, one tomato contained the equivalent levels of vitamin D as two medium-sized eggs or one ounce of tuna, the experts reported in an article published in Nature Plants.

Most vitamin D3 supplements come from lanolin, which is extracted from sheep’s wool.

Scientists are now evaluating whether the Sun, rather than ultraviolet light, can effectively convert 7-DHC to D3.

New UK regulations allow this theory to be tested, but it could be some time before it’s ready to hit supermarket shelves.

To close the current gap in vitamin D intake from dietary sources, two medium gene-edited tomatoes should suffice, said study lead author Jie Li. He added that it is difficult to distinguish one of that type from a wild one.