The growing interest in vitamin D is positively related to that of its kidney complications and is negatively related to that of bone benefit: an analysis based on Google Trends (Preprint)

Background. The benefits of vitamin D relate to muscle strength, cardiovascular health, and prevents osteoporosis. Objective. This study aimed to explore trends of global interest on vitamin D, hypercalcaemia, adverse kidney effects (stones and kidney failure) and osteoporosis. Methods. An electronic search was conducted with Google Trends, limiting searches based on the "health" criterion. Results. Worldwide interest in vitamin D3 (cholecalciferol), vitamin D2 (ergocalciferol or calciferol), kidney stones and kidney failure is progressively growing over time. On the other hand, vitamin D was found to be negatively correlated with hypercalcaemia and bone density. Another result of our analysis is the distribution of the popularity of searches across countries. In particular, the global popularity for vitamin D3 seems higher than that of vitamin D2 and also shows different geographical preferences. The growing interest in vitamin D parallels that of kidney stones and kidney failure, while decreasing popularity has been noted for hypercalcaemia and bone density. Conclusions. The research volumes help to clarify the changes in the trends of use of supplements and the development of their complications, according to the different geographical areas, socioeconomic status and online literacy