In 2012, Medicare paid almost $150 million in rebates for vitamin D testing. Most of this money would have been better spent on priority areas such as hospital beds or hepatitis C treatment. Medicare-rebatable criteria for vitamin D testing have been justifiably tightened. There has been no benefit demonstrated for testing low-risk groups, and although many in this sunburnt country ironically do return low-ish levels, it is rarely severe, and the clinical effects of mild-moderate deficiency are far from clear.
We know vitamin D has an important role in bone health. Low levels have also been associated with (but not proven causative in) diabetes, dementia, some cancers, autoimmune and cardiovascular disease.
Vitamin D toxicity is rare, and results from over-supplementation, not sunlight.
Vitamin D supplements are being increasingly used. About 10 minutes of mild sunlight exposure can provide about 10,000 international units (IU) of vitamin D, while most capsules provide only 1,000IU. The use of sunscreens may decrease, but not prevent, vitamin D absorption.
So remain sun-wise, but appreciate the many health and psychological benefits of a morning or afternoon walk, cycle or read in the sun.
