An analysis of U.K. resident’s respiratory outcomes and their associations with vitamin intakes found that individuals with a high intake of vitamins A, E, and D had fewer complaints related to respiratory health than those in lower intake groups. The analysis was published this month in the British Medical Journal.
 
The association was found for the intake of vitamins A and E derived from both foods and supplements, but the positive effect of vitamin D intake on respiratory health was only achieved if the vitamin was taken in through supplementation, not food, the authors of the study said.
 
The researchers drew results from 6,115 participants in the national survey program who had completed three or more days of diet diaries. The survey program itself relies on data sourced from 1,000 people each year who provide an annual summary of the foods and drinks they consume. In addition to accounting for dietary intake alone, researchers also analyzed dietary intake in combination with supplements, as well as other possible factors including BMI, smoking, total caloric intake, and household income. Respiratory complaints were self-reported by the participants, and were not limited to doctor’s visits.
 
Logistic regression adapted for complex survey design was used to investigate the relationship between each individual vitamin intake and self-reported respiratory complaints. No association was found between vitamin C intake and respiratory complaint instances.
 
“Our findings are consistent with the hypothesis that supplementation is critical to ensuring adequate vitamin D status is maintained, and potentially indicate that intake of vitamin D from diet alone cannot help maintain adequate vitamin D status,” the authors of the study concluded. “It is estimated that around a fifth of the general population in the UK have low vitamin D, and over 30% of older adults aged 65 years and above do not achieve the recommended nutrient intake.”
 
Because this is an observational study, the researchers caution that no cause can be established, and no inferences can be made in respect of the COVID-19 pandemic.
 
Those involved at NNEdPro Global Centre for Nutrition and Health, an institution which co-founded the journal BMJ Nutrition, Prevention, and Health commented on the study.
 
“While acknowledging the limitations of this data, it does add further to a growing body of interest and evidence for the role of vitamin D in respiratory health,” Shane McAuliffe, science communications lead for the NNEDdPro Nutrition and COVID-19 Taskforce, said. “Given our knowledge of the extent of vitamin D deficiency in the population, balanced with the low cost and low risk of adverse events, it seems sensible to provide supplementation of this key vitamin, particularly to those most likely to be deficient.”
 
“Nationally representative data continue to remind us that micronutrient deficiencies are far from a thing of the past, even in higher income nations like the UK, and this trend is mirrored by comparable global data sources from lesser resourced countries to those with advanced health systems.”