<p>If British scientists have their way, two medium-sized tomatoes a day could keep the doctor away.</p>.<p>A research team led by scientists at the John Innes Centre in Norwich have edited the genetic makeup of tomatoes to become a robust source of vitamin D, which regulates nutrients like calcium that are imperative to keeping bones, teeth and muscles healthy.</p>.<p>Although vitamin D is created in our bodies after exposure to sunlight, its major source is food, largely in dairy and meat.</p>.<p>Low vitamin D levels - associated with a plethora of conditions from cancer to cardiovascular disease - affect roughly 1 billion people globally, the researchers said.</p>.<p>Tomato leaves naturally contain one of the building blocks of vitamin D3, called 7-DHC. Vitamin D3 is considered best at raising vitamin D levels in the body.</p>.<p>Scientists used the Crispr tool - which is designed to work like a pair of genetic scissors - to tweak the plant's genome such that 7-DHC substantially accumulates in the tomato fruit, as well as the leaves.</p>.<p>When ultraviolet light was shined on leaves and sliced fruit for an hour, one tomato contained the equivalent levels of vitamin D as two medium-sized eggs or 28 grams (1 ounce) of tuna, the researchers wrote in a paper published in the journal Nature Plants.</p>.<p>Most vitamin D3 supplements come from lanolin, which is extracted from sheep's wool. Since the sheep stays alive, it works for vegetarians, but not vegans.</p>.<p>Lichen is considered a vegan source of vitamin D3, but the data underpinning its effectiveness is limited - and it is also expensive, said Susan Lanham-New, head of the department of nutritional sciences at the University of Surrey.</p>
<p>If British scientists have their way, two medium-sized tomatoes a day could keep the doctor away.</p>.<p>A research team led by scientists at the John Innes Centre in Norwich have edited the genetic makeup of tomatoes to become a robust source of vitamin D, which regulates nutrients like calcium that are imperative to keeping bones, teeth and muscles healthy.</p>.<p>Although vitamin D is created in our bodies after exposure to sunlight, its major source is food, largely in dairy and meat.</p>.<p>Low vitamin D levels - associated with a plethora of conditions from cancer to cardiovascular disease - affect roughly 1 billion people globally, the researchers said.</p>.<p>Tomato leaves naturally contain one of the building blocks of vitamin D3, called 7-DHC. Vitamin D3 is considered best at raising vitamin D levels in the body.</p>.<p>Scientists used the Crispr tool - which is designed to work like a pair of genetic scissors - to tweak the plant's genome such that 7-DHC substantially accumulates in the tomato fruit, as well as the leaves.</p>.<p>When ultraviolet light was shined on leaves and sliced fruit for an hour, one tomato contained the equivalent levels of vitamin D as two medium-sized eggs or 28 grams (1 ounce) of tuna, the researchers wrote in a paper published in the journal Nature Plants.</p>.<p>Most vitamin D3 supplements come from lanolin, which is extracted from sheep's wool. Since the sheep stays alive, it works for vegetarians, but not vegans.</p>.<p>Lichen is considered a vegan source of vitamin D3, but the data underpinning its effectiveness is limited - and it is also expensive, said Susan Lanham-New, head of the department of nutritional sciences at the University of Surrey.</p>