Scientists create tomatoes genetically edited to bolster vitamin D levels

Scientists have created genetically edited tomatoes that contain the same amount of provitamin D3 as two eggs or a small amount of tuna.

Tomatoes are expected to be tested in the UK next month, and if successful, could provide an important new source of vitamins D and E.

A majority of Britons have low levels of vitamin D, which is needed to keep bones, teeth and muscles healthy. Exposure to the sun converts provitamin D3 into an active form of vitamins D and E that our bodies can use.

In the UK, there is only enough sunlight to achieve this between April and September, meaning we have to rely on supplements or oily fish. Many supplements contain a substance from sheep's wool.

A professor of ecology at the University ofSouthampton said that genes editing tomatoes to accumulate provitamin D3 at levels above recommended guidelines could result in better health for many.

The tomato plants were created by using a technique called Crispr-Cas9 which is similar to a pair of tweezers.

The focus was on an enzyme in tomato plants that converts provitamin D3 into cholesterol. The researchers were able to block this pathway because of the provitamin D3 in the tomatoes.

The amount of provitamin D3 in one tomato fruit would be equivalent to two medium-sized eggs or 28 grams of tuna. The fruit would need to be exposed to UVB light in order for it to be converted into active vitamins D and D3. Nature Plants published the research.

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The chief scientific adviser at the Department for Environment, Food and Rural Affairs said that it was a nice example of the use of gene-editing technologies to make a very specific change to a crop.

Such crops are the subject of a bill, set out in the Queen's speech, which will allow gene-edited plants to be treated differently to genetically modified organisms.

It is an example of the type of product that could be passed through traditional legislation, but would take decades to navigate the system under the current regulatory environment.

The tomato plants do not contain genes from other organisms and could theoretically have been created through a process called selective breeding. The environment secretary has predicted that the proposed genetic technology (precision breeding) bill will be passed into law this year, which will allow the first gene-edited foods to be available by 2023.

The John Innes Centre supervised the study and it showed the potential for gene editing to be used to enhance the nutrition of foods.

The technique could work well in other solanaceous food crops such as peppers, chillis, potatoes and aubergines.

Martin said that growers could potentially sell the leaves or unripe fruits to supplement manufacturers for processing into vitamin D tablets.