Scientists have unlocked the vitamin D potential of tomatoes, study says

A gene-edited tomato (left) is shown in a side-by-side comparison with an unmodified tomato (right).

(CNN)Fish and dairy products are the best dietary sources of vitamin D, which can make it a struggle for those on a plant-based diet to get enough of the essential micronutrient. Vitamin D helps protect our bones and keep muscles and teeth healthy.

Now, a team of researchers have come up with a potential new and vegan source of vitamin D: tomatoes gene edited using CRISPR-Cas9 technology to contain a precursor to vitamin D.
If the process is adopted commercially by farmers and producers, these tomatoes could help address vitamin D insufficiency, which the study said affects 1 billion people globally.
    "This exciting discovery not only improves human health but contributes to the environmental benefits associated with more plant-based diets -- often linked with a challenge in securing some key vitamins and minerals widely found and bioavailable in animal products," Guy Poppy, a professor of ecology at the University of Southampton, told the Science Media Centre in London. He wasn't involved in the research.
      Vitamin D supplements are widely available in many countries, but coauthor Cathie Martin, a professor at the John Innes Centre in Norwich, England, said that eating a tomato was "so much better than taking a pill."
      "I think that having a dietary source (of vitamin D) in the form of a plant also means that you can get added benefit from eating tomatoes. We don't eat enough fruit and veg anyway. A tomato is a good source of vitamin C as well," she said at a news briefing.
      The study published Monday in the scientific journal Nature Plants.

        Sunshine vitamin

        The main source of vitamin D for most people is dietary, but our body also makes the micronutrient when skin is exposed to UVB light -- that's why it's sometimes called the sunshine vitamin. The scientists harnessed a similar process in tomato plants.
        The compound in the skin that can make vitamin D is known as 7-DHC, or provitamin D3, and it's also found in tomato plant leaves and unripe green fruit.
        The researchers blocked a gene in tomato plants that normally converts provitamin D3 into cholesterol, which enabled provitamin D3 to accumulate in the ripe tomat