Authors of a study alleging that there is no evidence that higher vitamin D levels are associated with lower risk of melanoma have conspicuously ignored the very nature of why The Sunshine Vitamin is involved in lower risk of most cancers.

The authors — reporting preliminary findings at a meeting of the Society of Investigative Dermatology — cited data suggesting that 600 IU supplements do not reduce risk of melanoma, despite the fact that other research suggests that higher vitamin D blood levels are linked to lower incidence of the disease.

“Vitamin D and skin cancer risk has been a really hot topic lately,” Dr. Maryam Asgari told MedPageToday.com. “There’s a whole lot of new evidence showing our vitamin D levels are probably insufficient, and vitamin D insufficiency may be linked with certain cancer risk. But the overall take-home message of our study is that vitamin D is not associated with decreased melanoma risk.”

Here’s why Asgari’s statement is completely wrong:

1. 600 IU of vitamin D is less than one-third what the vitamin D research community now suggests is necessary to maintain high enough vitamin D levels to realize the anti-cancer benefit of vitamin D. Asgari should have known that. Likely he started the study before that was widely known, but in reporting the study this week he should have known: 600 IU is an irrelevant amount for cancer research.
2. The study looked at vitamin D intake, but not vitamin D blood levels, the true end-point. Again, Asgari should have known that.
3. According to MedPageToday.com: “Note that this study was published as an abstract and presented orally at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.” Yet Asgari’s comments — and the headlines produced by his comments — are anything but preliminary.

Dermatology will fight the mounting evidence that natural vitamin D levels — levels only attained naturally through regular sun exposure — is related to a reduction of cancer risk, particularly melanoma risk.

Asgari’s uneducated yet overstated assertions seem to be one more example of this.