How much extra Vitamin C is essential for good health?

The pandemic is largely responsible for advocating the idea of proper intake of Vitamin C, known as an important immune-support nutrient and vital in helping the body protect itself from severe viral illnesses. But how much is the right amount needed for the body?

Research at New University of Otago, Christchurch in New Zealand has identified, for the first time, exactly how much extra Vitamin C humans need to ingest, relative to their body weight, to maximise their immune health.

Vitamin C is known to be essential for good immune function and works by helping white blood cells fight infection.

The study, published in the international journal Nutrients, found that for every 10 kg of excess weight a person carries, their body needs an extra 10 milligrams of Vitamin C daily, which will help to optimise their immune health.

"Previous studies have already linked higher body weight with lower Vitamin C levels," said lead author Associate Professor Anitra Carr from the University's Department of Pathology and Biomedical Science.

"But this is the first study to estimate how much extra daily Vitamin C is actually needed for people, relative to their body weight, to help maximise their health," she added.

Carr suggested the findings could potentially help heavier people better protect themselves from such illnesses because obesity is a known risk factor for Covid. Obese people can also be at increased risk of severe illness due to the infection.

The results from this study therefore suggest that increasing your Vitamin C intake if overweight might be a sensible response, Carr said.

Another major complication of Covid-19 is pneumonia. Patients with pneumonia are known to be low in Vitamin C.

Several research has shown that "Vitamin C decreases the likelihood of people getting pneumonia and decreases the severity of it, so finding the right levels of Vitamin C to take if you are overweight may help to better support your immune system", Carr said.

The study determined that someone weighing 90 kg would need to take an extra 30 milligrams of Vitamin C to achieve the optimal goal of 140mg/day; while someone weighing 120 kilograms would need at least an extra 40 milligrams of vitamin C daily to achieve the optimal 150mg/day.

The easiest way to increase daily Vitamin C intake is by upping the consumption of Vitamin C-rich foods such as fruits and vegetables or by taking a Vitamin C supplement, Carr said.