Children deficient in the vitamin can suffer seizures and rickets, and high levels are needed to maintain healthy teeth, bones and muscles.
But a combination of 'safe sun' advice—where almost any exposure to sunlight is considered dangerous—and a life spent indoors has meant an entire generation of young children is deficient in the vitamin.
As a result, family doctors have stepped in and are prescribing the supplements. Reports that cover 723 surgeries in the UK have found that 12,277 children were given prescriptions for the first time, suggesting a 25-fold jump between 2008 and 2016.
However, only a third of the children had symptoms of vitamin D deficiency, which can also include aches and pain, tiredness and fatigue, and doctors hadn't tested for any deficiency in most of the cases.