Vitamin D: Sunny days ahead

Going back to the basics might prove fruitful for functional-foods and supplements developers, who have caught wind of the voluminous research recently published on an old favourite: vitamin D.

Inklings of a possible connection between vitamin D and cancer first appeared back in 1941 when Dr Frank Apperly analysed North American cancer statistics and found that the closer one lived to the equator, the lower their cancer risk.

In the 65 years since, dozens of studies have shown that people living at higher altitudes have higher rates of everything from Hodgkin's lymphoma to colon, pancreatic, prostate, ovarian and breast cancers. We now know that the magic of sunlight is not so much the sunlight itself, but rather how the skin converts this light into vitamin D.

Just how crucial vitamin D may be to human health became even clearer in 2008, as study after study came out documenting its benefits on everything from cancer to dermatitis to heart disease. Given the attention these studies have generated in the media, a real opportunity awaits developers of functional foods and dietary supplements.

"Vitamin D will be strong (in 2009)," concurs Loren Israelsen, executive director of the United Natural Products Alliance and president of the LDI Group consultancy. "Almost everyone is taking too little."

The latest research
A September study in the American Journal of Epidemiology found increased intake of vitamin D may reduce the risk of breast cancer by more than 20 per cent.

In October, the Journal of Steroid Biochemistry and Molecular Biology published the results of a study that found that individuals with the highest blood level of 25-hydroxyvitamin D [or 25(OH)D] had the lowest risk of breast cancer. A meta-analysis of five colorectal cancer studies, published online in February 2008 in the American Journal of Preventive Medicine, found that raising the serum level of 25(OH)D to 34ng/ml reduced the incidence rates of colorectal cancer by half. The researchers projected a two-third reduction in incidence with serum levels of 46ng/ml, which corresponds to a daily intake of 2,000IU of vitamin D3.

While the spate of cancer-related research in 2008 fortified pre-existing theories, other research suggested a relatively novel benefit to vitamin D in heart disease. An Australian study found a seasonal pattern for heart failure peaking in winter months when vitamin D levels are typically low (Australian New Zealand Journal Public Health, October, 2008).

And a study conducted in Austria revealed a 284 per cent increased risk for heart failure and a 505 per cent increased risk for sudden-death heart attack among adults with low circulating vitamin D levels (Journal of Clinical Endocrinology Metabolism, October, 2008).

The recommendations
Studies like these captured the attention of health-advocacy groups, where calls to increase both the recommended dose and the tolerable upper intake level (UL) of vitamin D3 have become frequent.

In October, the American Academy of Pediatrics released a clinical report doubling the recommended amount of vitamin D for infants, children and adolescents to 400IU per day. This was a major leap over the 200IU previously recommended because it would require supplementation for all children. The report came on the heels of an April study in the Journal of Clinical Endocrinology & Metabolism, which recommended raising vitamin D levels to 2,000IU in children. After a literature review, the Council of Responsible Nutrition stated it believes the UL for vitamin D3 should be increased fivefold, to 10,000IU, above the current 2,000IU. The American Journal of Clinical Nutrition also agrees.

Finally, even the FDA took notice of vitamin D. In September, the agency approved a health-claim amendment, permitting products that bear a calcium and osteoporosis claim to also reference vitamin D content and its ability to benefit bone health. The change will take effect in 2010.

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