Are You Worried About Getting the Flu? Here’s How to Prevent it in Babies and Adults

According to the latest media reports, this season’s flu is more intense and occurring more often that it has in other recent years.  Studies have determined a nutrient can help prevent and shorten its symptoms in babies and adults. This flu season has been one of the worst in years in the US.  According to the Centers for Disease Control (CDC), 45 states have reported high rates of the flu almost four times higher than reports from 2017.

Babies are at an increased risk for contracting influenza due to the development of their early immune system. As the immune system is first developing in young infants and children, their immune cells must encounter many germs (bacteria and viruses, etc.)  in order to ‘recognize’ them. Additionally, because immunity is slowly but gradually strengthening, flu vaccines are not approved for infants under six months of age.

Vitamin D deficiency is a known risk factor for contracting the flu. In fact, many researchers believe it is the leading cause of winter epidemics, that occurs when our vitamin D levels drop due to decreased sunshine exposure.  Preceding studies have determined supplementation can assist with preventing and treating colds and the flu.

A new study evaluated the impact of vitamin D supplementation on management of influenza among infants. The study  included a 400 healthy babies between 3 and 12 months of age who did not have influenza

They were randomly placed in o one of two groups: 200 infants received 400 IU vitamin D drops every day for four months, while the other 200 received 1,200 IU vitamin D drops daily for four months. At the beginning of the study and every two months, their vitamin D and calcium levels were measured.

This is what the study found:

  • Of 121 cases of the flu in total, 78 and 43 cases of influenza A infection occurred in the 400 IU/day and 1200 IU/day vitamin D groups.
  • The babies receiving the higher dose of vitamin had a shorter duration of flu symptoms, coughing and wheezing.

The researchers concluded the results showed that high-dose vitamin D treatment promoted recovery Now, with the current flu season affecting so many individuals, it seems necessary to take precautionary measures to protect those most vulnerable around us. The Vitamin D Council recommends supplementing infants with 1,000 IU/day (25 mcg) with an upper limit of 2,000 IU (50 mcg). According to this study, 1,200 IU/day (30 mcg) was safe and effective in helping mediate influenza symptoms in 3-12 month old infants, which is consistent with our recommended ranges.

Also, a  meta-analysis of several studies published in the British Medical Journal has shown vitamin D reduced risk of the cold and flu in adults.

The Vitamin D Council recommends adults take at least 5,000 IU (125 mcg) and up to 10,000 IU (250 mcg) per day.


Zhou, J. et al. Preventive Effects of Vitamin D on Seasonal Influenza A in Infants: A Multicenter, Randomized, Open, Controlled Clinical Trial. Pediatric Infectious Disease Journal, 2018.

Peterson, R. & Cannell, JJ. RCT discovers 1,200 IU more effective than 400 IU in managing influenza in infants. The Vitamin D Council Blog & Newsletter, 1/2018.