There have been multiple studies that have correlated low vitamin D levels with increased infection and we now understand that vitamin D modulates both our innate and adaptive immune responses. This also ties into our understanding of the role seasons have in our fluctuating immune susceptibility. The cold weather we experience in winter doesn’t inherently cause a surge in influenza, but rather, the shorter days, decreased sunlight exposure leads to one thing – significantly less vitamin D – a biological breeding ground for illness susceptibility.

Highly active individuals are vulnerable to illness due to the increased physiological stress incurred by their body, as well as the depletion of resources and energy needed for muscle repair. Supplementing vitamin C and zinc ensures exercise does not deplete the range of nutrients needed for the maintenance of a healthy immunity.

When a virus or bacteria invades your body, zinc travels to key cells that help fight against infection and ensure that inflammation does not spiral out of control. Zinc deficiency affects the production and efficiency of immune cells, resulting in decreased host defence and increased risk of inflammation. Having adequate levels of zinc means your immune system is firing at optimal levels, even when your body is fatigued from training, avoiding sickness and subsequent lost training time.

Deficiencies in vitamin C ultimately result in impaired immunity and a higher vulnerability to infection. Vitamin C cannot be endogenously synthesised by humans and thus, requires an external source (diet or supplementation) to be obtained. Additionally, vitamin C is a water soluble compound, meaning it has a poor ability to be retained by the body and requires regular consumption.

Taken at the very first sign of illness will give you the best chance to reduce both the length and severity of any cold or related ailment. We also see many professional athletes cycle onto this supplement when training load is extremely high (e.g preseason) as a precautionary measure for compromised immunity through physical exertion. Zinc and Vitamin C are both water soluble so can be taken on an empty stomach, it’s also best to avoid taking this around any meals or drinks containing dairy.