“The bottom line is that the protective effects of vitamin D supplementation are strongest in those who have the lowest vitamin D levels and when supplementation is given daily or weekly rather than in more widely spaced doses. Vitamin D fortification of foods provides a steady, low-level intake of vitamin D that has virtually eliminated profound vitamin D deficiency in several countries. By demonstrating this new benefit of vitamin D, our study strengthens the case for introducing food fortification to improve vitamin D levels in countries such as the UK where profound vitamin D deficiency is common," said lead researcher Professor Adrian Martineau.
The findings were published in the The British Medical Journal.
Vitamin D supplementation significantly reduces the risk of flu among children, according to a study published in the American Journal of Clinical Nutrition. Researchers at the Jikei University School of Medicine in Tokyo, Japan examined up to 354 children who were given either vitamin D supplements or a placebo. Children in the treatment arm were given up to 1,200 international units of vitamin D over a period of three months.
Study data showed that children taking the vitamin supplements fell ill just as often as those who took a placebo during the first month of treatment. However, children in the supplement group showed a significant improvement in their overall health during the second month when their vitamin D levels had increased.
Researchers examined the vitamin's efficacy in flu protection against two anti-viral drugs zanamivir and oseltamivir. Study data showed that vitamin D supplementation helped reduce the risk of flu infection in children by up to 50 percent, compared with a measly eight percent reduction in children taking zanamivir and oseltamivir.
The scientists concluded that while generally effective, antiviral treatments will fail consistently when assessed against vitamin D. The findings explain why flu seasons peak during winter between December and March, when people have significantly low levels of the sunshine vitamin, researchers noted.
According to the World Lung Foundation, acute respiratory infections are associated with 4.25 million deaths around the world each year. Acute respiratory infections are also the third most common cause of death globally, and the leading cause of death in low- and middle-income countries. ARIs are also tied to at least six percent of the world's disability and death rates.
Data show that three to five million people around the world contract severe flu infections every year. As many as 500,000 people die of severe flu infections annually, researchers say. Acute respiratory infections are also more prevalent among highly susceptible populations such as patients with HIV.
Acute respiratory infections are the leading cause of disease and death in children around the world. According to the World Lung Foundation, 20 to 40 percent of all juvenile hospitalizations can be associated with acute respiratory infections.