Scientists Explore 'Aeronutrients' in Coastal and Rural Air as Possible Dietary Supplements

Researchers and nutrition scientists have proposed that tiny amounts of vitamins, minerals and helpful microbes in outdoor air — so-called "aeronutrients" and "aeromicrobes" — could modestly supplement dietary intake and help relieve symptoms linked to deficiencies such as fatigue, headaches and dry skin.

The theory, advanced in a paper by researchers including Dr. Flavia Fayet‑Moore of the University of Newcastle in Australia and published last year in Advances in Nutrition, argues that inhaled particles and gases from environments such as the coast or countryside could contribute to a person’s overall nutrient exposure. Inhalation would deliver those particles to blood vessels lining the mouth and nasal cavity, a route already used by some nutrient sprays.

Support for the concept comes from a range of small studies and environmental surveys rather than large clinical trials. A 2011 study by the National University of Ireland in Galway compared iodine levels in schoolchildren who lived near beaches with seaweed, beaches without seaweed and inland locations; the group near seaweed‑laden beaches had higher iodine levels, which researchers attributed in part to iodine gas released by seaweed into the air. In that analysis, investigators suggested airborne iodine might account for a substantial portion — as much as 40 percent in their estimates — of total iodine intake for some individuals.

Other research has pointed to differences in airborne microbial diversity between greener and more urban areas. A 2023 study led by researchers at the University of North Carolina found broader ranges of airborne bacteria in vegetated areas and suggested such exposure could influence immune functioning and the gut microbiome, with possible implications for overall health.

Proponents say aeronutrients could come from multiple environmental sources, including sea spray, decaying plant matter, soil and even molecules released while cooking. Some vitamins are already delivered by aerosol: vitamin B12 and vitamin D products are marketed in spray form and are absorbed rapidly through mucous membranes, lending plausibility to the idea that inhaled particles might enter the body by a similar route.

Public‑health context underscores why any additional source of micronutrients is of interest. Diet remains the principal source of vitamins and minerals, and many populations show shortfalls. In the United Kingdom, for example, around one in five adults is estimated to have insufficient vitamin D; UK health authorities advise most people to take a daily 10 microgram supplement, particularly in autumn and winter. Vegetarians and vegans are at higher risk of vitamin B12 deficiency because the vitamin is found mainly in animal products. Iodine deficiency can cause symptoms including fatigue, dry skin, weight gain and hair loss.

Not all nutrition scientists are persuaded that aeronutrients have meaningful public‑health impact. Tom Sanders, professor of nutrition and dietetics at King’s College London, described the idea as implausible, noting that dietary iodine generally depends on soil levels and food sources. Mike Lean, professor at the University of Glasgow, said that while the nose and lungs can absorb some nutrients, the concentrations of those nutrients in ambient air are usually far too small to prevent deficiencies.

Critics also point to alternative explanations for observed population differences, such as dietary patterns that might vary by coastal proximity or animals grazing on seaweed passing iodine into the food chain. Researchers acknowledge that many key questions remain unanswered: which nutrients circulate in air, in what forms and concentrations, how consistently exposures occur across environments, and whether inhaled amounts materially affect nutritional status.

Investigators call for further environmental sampling and controlled clinical studies to quantify airborne nutrient levels and to determine whether inhalation produces measurable health benefits. In the meantime, experts emphasize that ingestion of food remains the primary, evidence‑based source of essential nutrients and that known public‑health measures — including recommended supplements for groups at risk of deficiency — should be followed.

Walking by the sea or in green spaces carries other well‑established benefits, including physical activity and mental‑health advantages. Whether a seaside stroll will materially relieve symptoms of micronutrient deficiency by adding a measurable amount of vitamins or minerals through the air remains an open question pending more rigorous research.