There is controversy about Vitamin D supplements. At least there should be routine testing for deficiency covered by health insurance which it is not. With 7.4 % of Canadians reporting deficiency it is a public health issue.
“Prevalence rates of severe vitamin D deficiency, defined as 25(OH)D <30 nmol/L (or 12 ng/ml), of 5.9% (US) , 7.4% (Canada) , and 13% (Europe)  have been reported. Estimates of the prevalence of 25(OH)D levels <50 nmol/L (or 20 ng/ml) have been reported as 24% (US), 37% (Canada), and 40% (Europe).”
Cashman KD, Dowling KG, Škrabáková Z, Gonzalez-Gross M, Valtueña J, De Henauw S, et al. Vitamin D deficiency in Europe: pandemic? Am J Clin Nutr. 2016;103:1033–44. https://doi.org/ 10.3945/ajcn.115.120873
Schleicher RL, Sternberg MR, Looker AC, Yetley EA, Lacher DA, Sempos CT, et al. National estimates of serum total 25- Hydroxyvitamin D and metabolite concentrations measured by liquid chromatography–Tandem mass spectrometry in the US population during 2007–2010. J Nutr. 2016;146:1051–61. https://doi.org/10.3945/jn.115.227728
Sarafin K, Durazo-Arvizu R, Tian L, Phinney KW, Tai S, Camara JE, et al. Standardizing 25-hydroxyvitamin D values from the Canadian Health Measures Survey. Am J Clin Nutr. 2015;102:1044–50. https://doi.org/10.3945/ajcn.114.103689