Vitamin D blood levels, unnecessary prescriptions, and retest in naïve patients
Several studies in the last decade suggested a worldwide problem of vitamin D deficiency . Scientific societies generally support a blood concentration of 30 ng/ml as threshold for “insufficiency,”  despite 2011 recommendations by the Institute of Medicine stating that concentrations > 20 ng/ml provide no benefits on calcium absorption . Regarding clinical benefits, available evidence shows that vitamin D supplementation benefits specific subgroups of patients who are likely to be deficient, although most of them would not need testing (e.g., institutionalized people, patients with chronic kidney disease, pregnant women) [1, 3]. However, supplementation does not prevent cancer or cardiovascular disease [4, 5] or osteoporotic fractures in community-dwelling populations .
Nonetheless, widespread supplementation has gained popularity. In Italy, 10.5 defined daily doses (DDD) of vitamin D per 1000 inhabitants per day have been prescribed in 2017, with a 26% increase compared to...
Conceived of or designed study: G. Formoso, M. Marino, P. Ragni, R. Grilli, E. Maestri
Performed research: G. Formoso, M. Marino
Analyzed data: M. Marino, G. Formoso
Wrote the paper: G. Formoso
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 3.Ross AC, Manson JE, Abrams SA, Aloia JF, Brannon PM, Clinton SK, Durazo-Arvizu RA, Gallagher JC, Gallo RL, Jones G, Kovacs CS, Mayne ST, Rosen CJ, Shapses SA (2011) The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab 96:53–58CrossRefGoogle Scholar
- 5.Barbarawi M, Kheiri B, Zayed Y, Barbarawi O, Dhillon H, Swaid B, Yelangi A, Sundus S, Bachuwa G, Alkotob ML, Manson JE (2019) Vitamin D supplementation and cardiovascular disease risks in more than 83,000 individuals in 21 randomized clinical trials. A meta-analysis. JAMA Cardiol. https://doi.org/10.1001/jamacardio.2019.1870 [Epub ahead of print]
- 6.Kahwati LC, Palmieri Weber R, Pan H, Gourlay M, LeBlanc E, Coker-Schwimmer M, Viswanathan M (2018) Vitamin D, calcium, or combined supplementation for the primary prevention of fractures in community-dwelling adults. Evidence report and systematic review for the US Preventive Services Task Force. JAMA 319:1600–1612CrossRefGoogle Scholar
- 7.L’uso dei farmaci in Italia. Rapporto OsMed 2017. AIFA, July 2018 (available at http://www.aifa.gov.it/sites/default/files/Rapporto_OsMed_2017_AIFA.pdf)