29XP
Prevents a few respiratory infections (about 1 in 20 people helped) and shortens colds by about two days in pooled trials.
Immune & Cellular Health
Immune Resilience
Supplements and protocols ranked by XP
23XP
In a viral-challenge study using objective sleep tracking, people who slept less than 6 hours a night were roughly four times more likely to develop a cold after exposure than those sleeping over 7 hours.
Studies1
17XP
Ending showers with cold water led to fewer sick days off work, without fewer illness days.
Studies1
15XP
Does not prevent colds for most people, but may shorten them slightly.
Studies1
10XP
Lowers infection deaths in children who are deficient; little evidence of benefit for healthy adults.
10XP
Larger recent trials did not confirm earlier findings: across 46 trials, vitamin D did not clearly reduce respiratory infections.
