The correlation between vitamin D and PTH hormone was further demonstrated in a cross-sectional study, in which data were collected between 2011 and 2013 for vitamin and PTH in Brazil, and the results obtained showed high prevalence of vitamin D deficiency and insufficiency, mainly among older people, yet younger people had been affected as well; the low vitamin D levels were found to be negatively correlated with PTH [40]. Here, PTH is linked to vitamin D deficiency.