Comparison of Mineral Levels in Blood and Hair Samples of Healthy Adults: Evaluating the Clinical Utility of Hair Mineral Analysis

Minerals play vital roles in human physiology and immunity. Their tightly regulated levels in the human body can be easily measured in blood, but that only provides a snapshot of the mineral status at the time of collection. In contrast, human hair accumulates minerals over time and is less invasive to collect and store. This pilot study compared mineral levels in blood and scalp hair of generally healthy adults to determine whether hair can accurately detect clinically relevant mineral imbalances and evaluate whether a relationship exists between blood and hair measurements. Minerals tested included calcium, magnesium, sodium, potassium, copper, zinc, phosphorus, iron, and selenium. Correlation, linear regression, and agreement analyses were performed before and after statistical outlier removal. A total of 30 subjects (mean age: 69.8 years) participated in the study. Most minerals displayed no significant correlation between hair and blood values. However, a weak but significant inverse correlation between blood and hair was identified for phosphorus (p = 0.044 in correlation and linear regression analyses). Linear regression analysis before outlier removal also suggested a significant direct correlation of blood and hair values for zinc (p = 0.0315), but not after outlier removal (p = 0.2682). Agreement between mineral status in blood and hair (low, normal, high, based on established reference ranges) was non-significant for all minerals tested. In conclusion, a significant relationship between blood and hair mineral concentrations was not established. However, the distinct hair mineral analysis results suggest a unique clinical utility for long-term trends and imbalances.