The effect of vitamin C and D supplementation on immunity and performance in marathon runners

The effect of vitamin C and D supplementation on the immunity and performance of amateur marathon runners

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

REBEC

Registry ID

RBR-976s5yy

Enrollment

Registered

2026-03-31

Start date

2024-07-14

Completion date

Unknown

Last updated

2026-04-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Athletes

Interventions

The study is a randomized, parallel, double-blind, placebo-controlled clinical trial conducted with male triathletes enrolled in the Ironman 70.3 Aracaju 2024. its objective was to evaluate the effect

Eligibility

Sex/Gender

Male

Age

20 Years to 45 Years

Inclusion criteria

Inclusion criteria: Runners; male gender; marathon or ultramarathon runners for at least 3 years; aged between 20 and 45 years; training frequency of 3 days per week; average pace of 5:00 to 5:50 km/min in the last half marathon completed; no reported injuries in the last 6 months

Exclusion criteria

Exclusion criteria: Participants who are taking any other vitamin C and D supplements; have not completed a nutritional recall; or have completed a run longer than 5 km in the two days preceding the 42 km race will not be eligible

Design outcomes

Primary

Measure	Time frame
It is expected that supplementation with vitamins C and D will help improve the immunity and performance of marathon runners.	—

Secondary

Measure	Time frame
No secondary outcomes are expected	—

Countries

Contacts

Public ContactEder Magnus Filho

Programa de pós-graduação em Educação Física

edermagnus@gmail.com+55(79)998922007

Outcome results

None listed

Source: REBEC (via WHO ICTRP) · Data processed: May 1, 2026