Inclusion criteria	1. Aged 30 years or older
	2. Experienced ultramarathon runner (minimum five starts in distances over 42 km)
	3. Healthy
	4. No additional drug intake or smoking and good health status
	5. No additional vitamin D and antioxidant supplementation
Exclusion criteria	1. Physically or mentally compromised individuals (currently treated for a psychiatric disorder, or alcohol or substance abuse), unwilling or unable to comply with study evaluations
	2. Comorbidities causing severe inflammation: Addison’s disease, allergy, asthma, celiac disease, psoriasis, Raynaud’s disease, rheumatoid arthritis, systemic lupus erythematosus, type 1 diabetes, and other.