**Possible Involvement of Vitamin C in Periodontal Disease-Diabetes Mellitus Association**

**Maria Bogdan 1,**†**, Andreea Daniela Meca 1,**†**, Mihail Virgil Boldeanu 2,\*, Dorin Nicolae Gheorghe 3, Adina Turcu-Stiolica 4, Mihaela-Simona Subtirelu 4, Lidia Boldeanu 5, Mihaela Blaj 6,\*, Gina Eosefina Botnariu 7, Cristiana Elena Vlad 7, Liliana Georgeta Foia 8 and Petra Surlin 3**


Received: 1 February 2020; Accepted: 17 February 2020; Published: 20 February 2020

**Abstract:** Ascorbic acid (vitamin C) is an important water-soluble vitamin found in many fruits and vegetables. It has well-documented beneficial effects on the human body and is used as a supplement, alone or in combination with other vitamins and minerals. Over recent years, research has focused on possible new therapeutic actions in chronic conditions including periodontal disease (PD). We conducted a systematic review on clinical trials from four databases (PubMed, Clinical Trials, Cochrane, Web of Science) which measured plasmatic/salivary levels of ascorbic acid in PD–diabetes mellitus (DM) association. Six studies were included in our review, three of them analyzing patients with different grades of PD and DM who received vitamin C as a treatment (500 mg vitamin C/day for 2 months and 450 mg/day for 2 weeks) or as part of their alimentation (guava fruits), in combination with standard therapies and procedures. Decreased levels of vitamin C were observed in PD patients with DM but data about efficacy of vitamin C administration are inconclusive. Given the important bidirectional relationship between PD and DM, there is a strong need for more research to assess the positive effects of ascorbic acid supplementation in individuals suffering from both diseases and also its proper regimen for these patients.

**Keywords:** vitamin C; ascorbic acid; diabetes mellitus; periodontal disease
