ENDOCRINE PRACTICE Vol 16 No. 4 July/August 2010
To the Editor:
In his review article in the September/October 2009 issue of Endocrine Practice, “Is Vitamin D the Fountain of Youth?” Dr. Neil Binkley compares vitamin D with vitamin E and vitamin K (1).
This comparison is not justified because vitamin D is not a vitamin but a hormone.
Vitamin D deficiency is a hormonal deficiency – an extremely common endocrine disorder.
Similar to other hormonal deficiencies, hormone D deficiency (HDD) has a wide range of ill effects.
We endocrinologists should approach our treatment of HDD as we do hypothyroidism, diabetes, or hypogonadism. You do not promise someone a “fountain of youth” by prescribing levothyroxine, nor do you withhold insulin from a patient with type 1 diabetes because you need more studies to prove a causal relationship. Hormone D needs to be replaced in patients who have this disorder, and let us call this endocrine condition precisely what it is: hormone D deficiency or HDD.
Dr. Binkley seems to underestimate the power of the strong evidence linking HDD to a host of clinical manifestations by labeling published reports collectively as observational studies. In fact, many of the studies on hormone D are not simple observational studies. For example, in a laboratory model for multiple sclerosis, hormone D was shown to prevent this disease completely (2). In patients with diabetes, hormone D was shown to prevent the formation of foam cells, the building blocks of atheromatous plaque (3).
HDD is the result of our modern lifestyle and sun phobia, whereby skin cannot produce enough hormone D. Receptors for hormone D are present in numerous tissues – more specifically, bones, skeletal muscles, kidneys, islet cells, mononuclear cells, cardiomyocytes, and nervous tissues.
Thus, it is no surprise that HDD may lead to a wide array of clinical manifestations.
As endocrinologists, it is our responsibility to detect and treat HDD in all our patients. Furthermore, we need to educate our patients as well as other physicians about this very real endocrine disorder instead of questioning its serious nature by debating whether or not it fits the profile of the mythical fountain of youth.
DISCLOSURE
The author has no multiplicity of interest to disclose.
Sarfraz J. Zaidi, MD, FACP, FACE
Jamila Diabetes and Endocrine Medical Center, Inc.
1429 East Thousand Oaks Boulevard, Suite 105
Thousand Oaks, CA 91362; sjzaidi at onlinemedinfo.com
REFERENCES
1. Binkley N. Is vitamin D the fountain of youth? Endocr Pract. 2009;15:590-596.
2. Hayes CE. Vitamin D: a natural inhibitor of multiple sclerosis. Proc Nutr Soc. 2000;59:531-535.
3. Oh J, Weng S, Felton SK, et al. 1,25(OH)2 vitamin D inhibits foam cell formation and suppresses macrophage cholesterol uptake in patients with type 2 diabetes mellitus. Circulation. 2009;120:687-698.
A 6 minute video by Dr. Zaidi on HDD - April 2010
A few blog posts by Dr, Zaidi on HDD - 2010
Review of his book on the VitaminDWiki PDF just $5