Issue

Vol 134 No 1541: 3 September 2021

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Issue Summary

Article
SUMMARY

Vitamin D deficiency, supplementation and testing: have we got it right in New Zealand?

We tracked rates of vitamin D prescriptions in New Zealand between 2003 and 2019, finding that they increased 14-fold to more than 1 million prescriptions/year in 2019. Even though vitamin D tablets are cheap (less than 50c/tablet), the medication costs alone for vitamin D in 2019 were more than $1 million. To find out whether the increasing amount of vitamin D supplementation had actually prevented consequences of vitamin D deficiency, we tracked the annual numbers of hospital admissions in New Zealand for the consequences of vitamin D deficiency (rickets and osteomalacia). Despite the dramatic increase in prescriptions for vitamin D, the number of hospital admissions for rickets, osteomalacia, and unspecified vitamin D deficiency remained small and stable, between 10 and 20 cases/year. Lastly, we assessed vitamin D measurements in Auckland in two time periods, 2002 and 2003 and 2009 and 2019, finding that vitamin D results increased between the two periods, partly as a result of increasing vitamin D prescriptions, but importantly, most tests in the later time period simply identified individuals with normal levels. Collectively, these results suggest that guidance and practice around vitamin D in New Zealand should change, because the costs of increasing vitamin D supplementation and poorly targeted testing could be better spent on different approaches to prevent osteomalacia and rickets

Article
SUMMARY

Vitamin D deficiency, supplementation and testing: have we got it right in New Zealand?

We tracked rates of vitamin D prescriptions in New Zealand between 2003 and 2019, finding that they increased 14-fold to more than 1 million prescriptions/year in 2019. Even though vitamin D tablets are cheap (less than 50c/tablet), the medication costs alone for vitamin D in 2019 were more than $1 million. To find out whether the increasing amount of vitamin D supplementation had actually prevented consequences of vitamin D deficiency, we tracked the annual numbers of hospital admissions in New Zealand for the consequences of vitamin D deficiency (rickets and osteomalacia). Despite the dramatic increase in prescriptions for vitamin D, the number of hospital admissions for rickets, osteomalacia, and unspecified vitamin D deficiency remained small and stable, between 10 and 20 cases/year. Lastly, we assessed vitamin D measurements in Auckland in two time periods, 2002 and 2003 and 2009 and 2019, finding that vitamin D results increased between the two periods, partly as a result of increasing vitamin D prescriptions, but importantly, most tests in the later time period simply identified individuals with normal levels. Collectively, these results suggest that guidance and practice around vitamin D in New Zealand should change, because the costs of increasing vitamin D supplementation and poorly targeted testing could be better spent on different approaches to prevent osteomalacia and rickets