Giving children high doses of vitamin D does not reduce their chances of getting viral upper respiratory tract infections (URTIs), new research suggests.
Epidemiological studies support a link between low 25-hydroxy-vitamin D levels with a higher risk of viral URTIs. However, whether winter supplementation of vitamin D reduces the risk has not been established.
In a new randomised clinical trial, 349 children aged 1-5 years received 2000IU/d of oral vitamin D supplementation (high-dose group) for a minimum of four months between September and May, while a second group of 354 children received 400 IU/d (standard-dose group). However, higher dose supplementation did not succeed in reducing the rate of viral URTIs.
There was no statistically significant difference in the number of laboratory-confirmed infections or the number of parent-reported upper respiratory tract illnesses between groups. There was no a significant difference between the groups in the median time to first infection.
“We may have just busted a myth,” said lead author, Dr Jonathon Maguire, from St Michael’s Hospital in Toronto, Canada. “More is not always better. Our findings do not support the routine use of high dose vitamin D supplementation for the prevention of wintertime upper respiratory tract infections among healthy children.”