Low serum vitamin D levels may be linked to a higher risk of mouth cancer Original paper

In this meta-analysis of observational studies, serum levels of vitamin D were lower in adults with mouth cancer than in adults without the disease.

The association between mouth cancer risk and (i) the intake of folic acid and (ii) serum levels of vitamin D.

A total of 102,098 men and women (90,011 for folic acid and 12,087 for vitamin D), of whom 1,458 developed mouth cancer.

A meta-analysis of 6 observational studies (including cohort and case-control studies) was performed. The studies were conducted in Europe (4 studies), North America (1 study), and South America (1 study). The follow-up periods ranged from 5 to 26 years.

The serum levels of vitamin D were lower in the participants with mouth cancer than in the participants without mouth cancer. No association was found between the intake of folic acid and mouth cancer risk. The certainty of evidence was rated moderate.