Sixty per cent of Australians lack vitamin D. That's no small-fry figure.
Vitamin D is often ‘overlooked', despite the number of people at risk of deficiency-induced metabolic bone disease, Dr Peter Rohl, senior staff specialist at Sydney's St George Hospital, recently told the Australian Journal of Complementary Medicine. "It wouldn't burst the health budget to actually have a vitamin D measurement of almost all your patients at some stage," he said.
What is it good for?
Somewhat of a ‘wonder vitamin', the answer is multi-fold. New research backing the benefits of vitamin D continues to spring forth, the most well-accepted of which centres on treatment and prevention of osteoporosis, cardiovascular disease and craniotabes – an abnormal softening of the skull bones in breastfed babies born to vitamin D deficient mothers.
A recent US analysis found that vitamin D intake of over 600 IU per day (from milk, fish, supplements and sunlight exposure) reduces the risk of osteoporosis by 27 per cent.
Another study from the same country, reported that people with moderate vitamin D deficiency are 62 per cent more likely to suffer heart attack, stroke or heart failure than those with high levels of the vitamin. "This is the first study that has produced any real evidence that there is a relationship between low vitamin D levels and cardiovascular disease," says a cardiologist from Royal Prince Alfred Hospital, Professor Phil Harris.
Similarly, a Sydney-based study into vitamin D levels in pregnant women found that 15 per cent were classified as ‘severely deficient' while a Japanese study into the incidence of craniotabes found that 22 per cent of newborn babies examined had the condition. Vitamin D deficiencies are linked with contributing to lower birth weights, and, (when coupled with calcium deficiencies) higher risk of infant seizures.
Where does it come from?
Vitamin D is primarily produced from exposure to sunlight, yet small amounts can also be absorbed from foods such as oily fish, liver and eggs. It follows that we're not getting enough sun or consuming sufficient levels of these key foods.
How much do we need?
It depends on how much sun we get. For those living in southern states, the Cancer Council recommends two to three hours of sun exposure per week at this time of year. Most people can achieve adequate levels by being outdoors with typical day-to-day activities – outside peak UV periods, that is.
For those gaining enough sun, Osteoporosis Australia says 400-800 IU of vitamin D daily will suffice. But for those who don't, 800-2000 IU is called for. Others within the medical fraternity, such as Professor Rebecca Mason of the Bosch Institute at the University of Sydney, claim daily intake needs rise to 1000 IU.
The future is D
A major problem, believes Professor Mason, is the absence of high dose vitamin D supplements on the market – which could be used to treat those with moderate to high deficiencies. Australian scientists are currently looking into the feasibility of vitamin D injections of around 600,000 IU (potentially a year-long dosage).