Finding it hard to raise levels of Vitamin D, popularly known as the sunshine vitamin? Scientists have developed gene-edited tomatoes that could be a simple and sustainable innovation to address the global health problem.

Researchers at John Innes Centre in the UK used gene editing to turn off a specific molecule in the plant's genome which increased provitamin D3 in both the fruit and leaves of tomato plants. It was then converted to Vitamin D3 through exposure to Ultraviolet B light.

Vitamin D is created in our bodies after skin's exposure to UVB light, but the major source is food. This new biofortified crop could help millions of people with Vitamin D insufficiency, a growing issue linked to a higher risk of cancer, dementia, and many leading causes of mortality, according to the study, which appears in the journal Nature Plants.

Tomatoes naturally contain one of the building blocks of Vitamin D3, called provitamin D3 or 7-dehydrocholesterol (7-DHC), in their leaves at very low levels. Provitamin D3 does not normally accumulate in ripe tomato fruits.

Researchers used CRISPR-Cas9 gene editing to make revisions to the genetic code of tomato plants so that provitamin D3 accumulates in the tomato fruit. The leaves of the edited plants contained up to 600 micrograms of provitamin D3 per gram of dry weight. The recommended daily intake of vitamin d is 10 micrograms for adults.

When growing tomatoes leaves are usually waste material, but those of the edited plants could be used for the manufacture of vegan-friendly Vitamin D3 supplements, or for food fortification.

"We've shown that you can biofortify tomatoes with provitamin D3 using gene editing, which means tomatoes could be developed as a plant-based, sustainable source of vitamin D3," said Professor Cathie Martin, corresponding author of the

"Forty per cent of Europeans have vitamin D insufficiency and so do one billion people worldwide. We are not only addressing a huge health problem but are helping producers, because tomato leaves which currently go to waste, could be used to make supplements from the gene-edited lines," Martin added.

The study noted that the provitamin D enriched tomatoes could be much helpful for people adopting a plant-rich, vegetarian or vegan diet, and for the growing number of people worldwide suffering from the problem of vitamin D insufficiency.