We've known for quite some time that greater skin pigmentation as well as living in higher latitudes (farther from the equator) is associated with lower vitamin D levels. So perhaps it wasn't too much of a surprise to find that African Americans w/MS had a lower vitamin D level (29.7nmol/L = 11.9ng/mL) than their controls (36.6nmol/L = 14.7ng/mL).
But what I found frightening is that 71% of controls were vitamin D deficient (<50nmol/L = <20ng/mL) and that 93% were insufficient (<75nmol/L = <30ng/mL).
Now, if this was the first study demonstrating a link between vitamin D & MS, I'd urge caution. Remember, look for trends rather than flukes. However, another case-control study published in the same journal this past February offers physiologic plausibility by linking sun exposure & vitamin D levels to central nervous system demyelination.
Furthermore, a twin-twin study published almost 3 years ago offers evidence of a genetic basis for seasonal regulation of vitamin D in those affected by MS. So, should we all start pumping up our vitamin D levels or at least enjoying the sunshine a bit more with the onset of summer? Unfortunately, it's still a bit early to make conclusive recommendations based upon associative & observational data. Remember that we still don't have cause & effect evidence, just the basis for developing a randomized controlled trial. And don't forget that sun exposure has been linked to skin cancer.
No comments:
Post a Comment