Newborns with the deficiency are 44 per cent more likely to suffer from schizophrenia when they are adults, say researchers from the University of Queensland.
The researchers think schizophrenia could have its roots in the womb when the developing baby is totally reliant on the mothers' own vitamin D stores. Making sure pregnant women have adequate levels of the vitamin—either by supplementing, eating foods rich in vitamin D—such as beef liver, cheese and eggs—or sunbathing.
The researchers analysed data on 2,602 people, born between 1981 and 2000 when their vitamin D levels were measured, who went on to develop schizophrenia. Neonatal levels of the vitamin were also measured among a similar group who didn't develop schizophrenia.
The risk is greater in northern countries that have less sunshine than Australia, the researchers say, and so ensuring high vitamin D levels, especially in pregnant women, is paramount.
The researchers now want to test if low vitamin D levels in women are also contributing to the autism epidemic.