The University of Sydney have undergone one of the largest Australian studies on vitamin D deficiency ever undertaken and results show that, despite previous findings, the deficiency is most prevalent during spring, and more serious than it was previously believed to be.
By Chloe Schneider
Professor Steven Boyages from Sydney Medical School said, “Vitamin D deficiency is implicated in a number of serious diseases including diabetes and cancer so improving our understanding is critical. The fact that the government-subsidised cost of testing for deficiency was $96.7 million in 2010 and rising is another reason better knowledge is important.”
The study looked at vitamin D levels in over 24,000 samples taken from walk-in patients and inpatients in NSW between July 2008 and July 2010. It investigated the effect of age, gender, season, socioeconomic status and remoteness on results.
Interestingly, the results showed that vitamin D levels reached their lowest point in both women and men during spring rather than winter as had previously believed to be.
The study published in Clinical Endocrinology says, “Even by December, the first month of summer, levels were still 46 percent below their peak. Although levels of ultraviolet-B radiation, the body’s principal source of vitamin D, would be rising by then, this reflects the time it takes to replenish the body’s stores.”
The study also identified a previously unknown risk group as females between 20 and 39 years of age.
Those taking vitamin D supplements should be mindful of the seasonal adjustment. The study suggests that supplement use should commence or increase at the end of summer and be maintained until the end of spring. During the summer months, supplement use could be decreased or stopped depending on individual’s exposure to sunlight.
Vitamin D plays a crucial role in the absorption and metabolism of calcium and phosphorous, acts as an immune system regulator, and has been linked to maintaining a healthy body weight and keeping the brain working later in life.
