Sunshine, vitamin D and oral health

Poor oral health, in particular dental caries and periodontal disease, is a common problem in the UK population. Previous research has suggested an association between vitamin D deficiency and increased risk of poor oral health. The main source of vitamin D for people resident in the UK is via exposure to solar irradiance. This study aims to determine if an association exists between sunshine exposure and better oral health, also specifically asking if increased exposure to UVB light between the wavelengths 290-315 nm approximately, from natural or artificial sources, affects the incidence of caries and periodontal disease. The findings of the study aim to inform novel public health measures to improve oral health. Following a review of the existing literature and a scoping review of previous relevant studies, a protocol was developed and a systematic review undertaken. The findings supported the presence of a positive association, but highlighted the lack of good quality observational trials and cohort studies. The scoping review highlighted a number of ecological studies, which further supported the existence of an association, but were outdated and limited in their methodology. These studies inspired the empirical studies undertaken in this thesis which used secondary data from modern epidemiological studies to investigate the hypothesis further. The findings of these studies suggested that increased exposure to sunshine is associated with a small, but consistent, reduction in the presence of dental caries in children in the UK. The evidence did not support an association between sunshine hours and a reduction in the prevalence of periodontal disease. Further research could focus on repeating these analyses using other datasets to see if relationships are replicated. Furthermore, the relationship between sunshine and other pertinent oral health outcomes such as oral cancer should be considered. Longer term studies could be undertaken using more accurate personal exposure measures and personalised health data, a viable possibility with the increasing use of wearables for data collection. This research undertaken uses a novel approach to investigate the relationship between sunlight, UVB and oral health, and to inform future public guidance, policy and health interventions.