Eating two kiwifruit each day could help keep muscles in top form, according to new research.
A University of Otago study, which was recently published in the American Journal of Clinical Nutrition, looked into what role vitamin C played in the body.
Lead researcher in the project, Professor Margreet Vissers, said muscles that support and move the skeleton were sensitive to changes in vitamin C intake.
If consumption of the vitamin dropped below optimal levels, muscle function could also fall.
The researchers gave 54 males aged 18-35 either half a kiwifruit or two kiwifruit every day over six weeks, and then measured the vitamin C content in their muscles.
They found general energy levels were increased with the "two per day" kiwifruit dose, something the researchers think comes from the optimal muscle function.
Vissers said eating kiwifruit was an efficient way to get vitamin C because it had much higher levels than other fruits and vegetables.
"Many people think that all fruit and vegetables are equally able to supply vitamin C, but this is not the case," she said.
"The levels in food vary hugely across the spectrum. We should eat a good range daily, but because many fruit contain only one-tenth of a healthy daily vitamin C requirement, we would recommend at least one serve per day of a high-value food like kiwifruit."
The study was part of a longer-term research project looking into vitamin C in the human body, and was funded by Zespri International and the University of Otago.