Increased 25(OH)D3 Level in Redheaded People: Could Redheadedness Be an Adaptation to Temperate Climate?

This study found that redhaired individuals consistently had higher calcidiol levels compared to non-redhaired subjects, suggesting a physiological adaptation for vitamin D synthesis in low UV-B conditions.

This study found that redhaired individuals exhibit higher calcidiol levels compared to non-redhaired individuals, suggesting a possible evolutionary adaptation for vitamin D photosynthesis in low UV-B environments in Europe.

This study found that alopecia in hereditary resistance to 1,25(OH)2D may indicate a more severe form of the condition, associated with earlier diagnosis and different responses to calciferol therapy.

Fair skin, not red hair, affects health due to possible vitamin D deficiency.

In this study, analysis of questionnaire data from over 111,000 respondents revealed that red hair is significantly associated with a higher level of mental health problems in both men and women, while red-haired women also exhibited poorer overall physical health.