The study, published in the journal Nutrition Reviews, shows that bleeding of the gums on gentle probing, or gingival bleeding tendency and also bleeding in the eye, or retinal haemorrhaging, were associated with low vitamin C levels in the bloodstream.

"When you see your gums bleed, the first thing you should think about is not, I should brush more. You should try to figure out why your gums are bleeding. And vitamin C deficiency is one possible reason," said lead author Philippe Hujoel from the University of Washington in the US.

For the study, the team analyzed published studies of 15 clinical trials in six countries, involving 1,140 predominantly healthy participants.

The results showed that bleeding of the gums on gentle probing, or gingival bleeding tendency, and also bleeding in the eye, or retinal haemorrhaging, were associated with low vitamin C levels in the bloodstream.

And, the researchers found that increasing daily intake of vitamin C in those people with low vitamin C plasma levels helped to reverse these bleeding issues.

The researcher recommends people attempt to keep an eye on their vitamin C intake through incorporation of non-processed foods such as kale, peppers or kiwis into your diet, and if you can't find palatable foods rich in vitamin C to consider a supplement of about 100 to 200 milligrams a day.