Active Cold and Flu Season Linked to New Influenza Variant

This cold and flu season is turning out to be quite intense, and it’s largely because of a new variant of the influenza virus known as subclade K.

According to the Centers for Disease Control and Prevention, around 19 million individuals have contracted the flu, which has led to approximately 250,000 hospitalizations and 10,000 deaths this season.

While there’s some good news—flu activity in the U.S. has dropped over the last three weeks—it still remains at a concerning level across the nation.

To help prevent getting sick, health experts recommend getting a flu shot, washing hands frequently, and steering clear of those who are ill.

Interestingly, researchers are now suggesting another potential ally in the battle against influenza: vitamin D.

You might know it as the “sunshine vitamin,” since our skin produces it when exposed to sunlight.

Vitamin D plays a crucial role in supporting our immune system. It helps generate antimicrobial peptides that combat viruses and bacteria while also tempering excessive inflammation.

Recent research from the University of Surrey in the UK revealed that adults suffering from severe vitamin D deficiency had a 33% higher chance of being hospitalized for respiratory infections compared to those with adequate vitamin D levels.

“Vitamin D is vital for our overall health,” stated Abi Bruneau, a postdoctoral researcher involved in the study. “Beyond benefiting our bones and muscles, its antibacterial and antiviral traits may lessen the risk of respiratory infections that lead to hospitalization.”

Influenza, along with bronchitis and pneumonia, falls under the category of respiratory infections. Older adults face a greater risk for such infections due to factors like declining lung function and an naturally weakened immune response.

The National Institutes of Health suggests that daily vitamin D intake should be about 600 international units, or 15 micrograms for those aged 1 to 70. Infants require 400 units, whereas individuals over 70 should take 800 units (20 micrograms).

Vitamin D levels can be checked through a blood test. Bruneau’s team defined severe deficiency as having less than 15 nanomoles per liter, while adequate levels were set at 75 nmol/L or higher.

From analyzing data involving 36,200 participants, researchers found that for every incremental increase of 10 nmol/L in vitamin D, the risk of hospitalization due to respiratory infections dropped by 4%.

This research was released in the February edition of the American Journal of Clinical Nutrition.

Andrea Darling, a postdoctoral researcher and lead author of the study, noted that the significant link between higher vitamin D levels and reduced hospitalization rates calls for more investigation. “It suggests that vitamin D supplementation and consuming vitamin D-fortified foods could help lessen the likelihood of hospitalization due to respiratory infections,” she pointed out.

The sun remains the primary natural source of vitamin D for most people.

Other sources include fatty fish like salmon and mackerel, fish liver oil, beef liver, egg yolks, cheese, as well as fortified milk, cereals, and orange juice.

Over-the-counter vitamin D supplements are readily available for just a few cents per pill.

Bruneau emphasized that taking vitamin supplements, particularly in winter when sun exposure is limited, is a practical approach to boosting vitamin D levels and decreasing the risk of severe respiratory infections. “This is especially crucial for older adults, who are at greater risk of serious consequences from these infections,” she concluded.