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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Louisiana vitamin D levels: an intriguing study

“The city of New Orleans runs on a different schedule than most other American cities,” says Dr. Mariam Gangat and colleagues at the Ochsner Clinic Foundation in New Orleans (latitude 29 degrees). Not only is that true, it is true about vitamin D levels too.

The good doctors found that seasonal vitamin D levels in newborn infants were different in New Orleans compared to the majority of the United States. The lowest levels were in summer and winter, and the highest levels in autumn and spring. This is due to the stifling summer heat driving pregnant women indoors.

Gangat M, Ponnapakkam T, Bradford E, Katikaneni R, Gensure R. Reversed Seasonal Variation in Maternal Vitamin D Levels in Southern Louisiana. Clin Pediatr (Phila). 2012 May 7.

The authors measured levels in 68 newborns (cord samples) and then again, when the infants were 2 and 4 months of age. The average cord level was 23 ng/ml. African American babies had average levels of 17 ng/ml, while white babies had 28 ng/ml, a racial inequity that America seems in no hurry to solve.

They could find no correlation between cord birth levels and subsequent levels in the breast-fed babies. The authors quoted Professor Hollis’s work on the vitamin D content of breast milk but missed the reason that mom’s level and baby’s levels did not correlate. As Hollis has shown, the moms’ levels were certainly not high enough to put vitamin D into their breast milk, thus all the babies either were on formula, supplements or got a little sun.

They pointed out that pregnant women taking a prenatal vitamin are still at risk for vitamin D deficiency. They also pointed out that the American Academy of Pediatrics still recommends that infants under six months avoid direct sunlight. Both of these statements are true, and I believe both need to change.

  About: John Cannell, MD

Dr. John Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr. Cannell holds an M.D. and has served the medical field as a general practitioner, emergency physician, and psychiatrist.

2 Responses to Louisiana vitamin D levels: an intriguing study

  1. People in Louisiana may be avoiding the hot sun like those in Middle East – May 2012
    title of page on VitaminDWiki:
    http://www.vitamindwiki.com/tiki-index.php?page_id=2701
    This inverse seasonal relationship was first seen about 5 years ago in the Middle East and other countries which can afford air conditioning.

  2. drfitness says:

    Confounding variables would also include skin color, sunscreen use, and cholesterol levels. If these vary, when compared with other regions, then the study results are weakened.