Three researchers who worked on a project in their own time using strands of their own hair have discovered that it’s possible to measure Vitamin D levels using human hair.

The discovery, potentially a major innovation in vitamin D measurement, could eventually prove a viable, more effective method of assessing a person’s long term vitamin D status.

The researchers, from Trinity College Dublin (TCD), and St James Hospital, say the study paves the way for improved diagnosis of vitamin D deficiency.

Eamon Laird, Nutrition Research Fellow at TCD, provided a beard sample, and hair samples were provided by his fellow researchers, Lina Zgaga, Associate Professor in Epidemiology, TCD and Martin Healy, Principal Biochemist from the Biochemistry Department in St. James's Hospital.

Dr Laird said they “tweaked” a technique for steroid hormone extraction from hair to create “our own recipe” for extraction of vitamin D.

“It worked,” he said.

Dr Zgaga said the study, published in the international journal of human nutrition, Nutrients, "presents the first step towards the development of a novel test for assessing vitamin D status over time”.

Dr Laird said other applications could include historical samples from archaeological sites.

“Hair, along with teeth, are some of the longest lasting surviving biological materials after death and thus it could be possible to for the first time assess the vitamin D status of historical populations,” he said.

Dr Laird said it could also be used to measure vitamin D status of ancient species “given the well preserved and copious amounts of, for example, mammoth or ancient ice age animal hair, often found from the warming permafrost and in museum specimens”.

More than one billion people worldwide are estimated to suffer from Vitamin D deficiency which is linked to poor bone health, but could also be a risk factor for depression, cardiovascular disease, inflammation, diabetes and cancer.

Dr Healy said finding that vitamin D can be measured in hair samples “potentially opens up a new approach to epidemiological studies relating the vitamin to bone and non-bone related medical conditions which have been associated with its deficiency”.

Dr Zgaga said further research is needed “to establish the exact relationship between vitamin D concentration in the blood and in hair over time”.