Fingernails as a mirror of nutrition
Study shows potential for health monitoring

17 Nov 2025
Stands in the Karl department stores' where the nail samples are handed in and the questionnaires are filled in.

Hands-on campaign in summer 2024 at Kaufhaus Karl: University members and members of the public handed in fingernail samples and completed a questionnaire on nutrition, health and lifestyle.

A research team led by Professor Dr Marc Birringer has developed an approach that allows lifestyle and nutrition to be recorded non-invasively using fingernail samples.

In the "Fulda NutriNAIL" study, the team first studied the mineral composition of the fingernails of 184 test subjects aged between 18 and 81 years. The results were then linked to the subjects' dietary habits, supplement intake, health information and characteristics of the nail surface. The fingernail samples were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), a powerful method for multi-element determination. Scientists from the fields of Nutritional, Food and Consumer Sciences, Computer Science and Public Health were involved.

"To date, there has been little research into mineral content as a biomarker for the assessment of lifestyle and dietary habits," explains Professor Birringer. "Nail samples are mainly used for toxicological tests for heavy metals. However, we wanted to know to what extent they could also be used for health monitoring."

Fingernails store mineral patterns

The results of the study published in the academic journal BioFactors show that fingernails store characteristic mineral patterns: Fingernails store characteristic mineral patterns that allow conclusions to be drawn about nutrition and lifestyle factors. For example, the nails of people who took selenium supplements had around 20 per cent higher selenium levels. Those who ate an omnivorous diet, i.e. without restrictions, had a higher selenium content than people with a vegan and vegetarian diet.

Certain nail changes were also noticeable, such as brittle nails, longitudinal grooves or white spots, which were associated with deviations in potassium, potassium, sodium and chromium levels. Analyses of the mineral pairs potassium and sodium as well as calcium and phosphorus should provide further insights into nutritional behaviour and lifestyle in the future.

"We can show that fingernail analyses are a cost-effective, non-invasive method for nutrition and prevention research that is suitable for everyday use," says Professor Birringer. In the future, the data collected in Fulda will be linked to AI-supported image analyses of nail surfaces in order to detect risks of micronutrient deficiencies at an early stage.

Original publication:
https://doi.org/10.1002/biof.70056

Academic contact person:
Professor Dr Marc Birringer
Email: marc.birringer@oe.hs-fulda.de