A few decades ago it was common knowledge that one of the main reasons for bleeding gums is low vitamin C intake. This fact has been forgotten a little, and modern dentistry tends to encourage brushing  and flossing only, with the assumption that people ’s vitamin C intake is adequate.  

A meta-analysis published in 2021 came to a different conclusion. They summarized the results of 15 clinical trials and one observational study. Their conclusion was that people whose vitamin C provision was low were 50% more  prone to have bleeding gums than people with higher levels of vitamin C.  

Vitamin C supplementation significantly decreased periodontal bleeding for people with low vitamin C intake, but was less useful or useless for those whose intake was adequate. 

The main author of the analysis believes that the necessary daily intake prescribed was determined with scurvy prevention in mind, but 100-200 mg would be needed to prevent bleeding gums and other capillary issues. If one can’t get this amount through diet, it’s strongly recommended to use dietary supplements, so they can easily and affordably prevent minor and major issues rooted in vitamin C deficiency.