Deficiency in vitamin D -- the 'sunshine vitamin' -- among older adults is associated with a substantial increased risk of depression resulting to early death, says a new study.

The study showed that vitamin D deficiency was associated with a 75 per cent increase in the risk of developing depression.

"This study shows that vitamin D is associated with a health condition other than bone health. What is surprising is the large effect on depression even after accounting for other control variables," said Eamon Laird, research candidate from the University of Dublin in Ireland.

"Given that vitamin D is safe in the recommended intakes and is relatively cheap, this study adds to the growing evidence on the benefits of vitamin D for health," said Laird. 

For the study, published in The Journal of Post-Acute and Long-Term Care Medicine (JAMDA), the team studied 4,000 community-dwelling people aged above 50 years.

"The new finding that the development of depression could potentially be attenuated by having a higher vitamin D status could have significant policy and practice implications for government and health services," said Rose Anne Kenny, Principal Investigator from the varsity. 

"It is our responsibility to now ascertain whether supplementation will influence depression," she noted. 

Another study, led by researchers from The University of Queensland (UQ) in Australia and published in Scientific Reports, showed that newborns with vitamin D deficiency had a 44 per cent increased risk of being diagnosed with schizophrenia as adults.

These findings are important as vitamin D status is relatively easy and inexpensive to modify through supplementation or fortification, the researchers noted.