Intervention and Prevention
Obesity (2008) 16, 90–95. doi:10.1038/oby.2007.23
Vitamin D Status and Response to Vitamin D3 in Obese vs. Non-obese African American Children
Kumaravel Rajakumar1, John D Fernstrom2,3,4, Michael F Holick5,6, Janine E Janosky7 and Susan L Greenspan8
- 1Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- 2Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- 3Department of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- 4Department of Neuroscience, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- 5Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, USA
- 6Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts, USA
- 7Department of Family Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- 8Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
Correspondence: Kumaravel Rajakumar, (Kumaravel.Rajakumar@chp.edu)
Received 24 February 2007; Accepted 29 May 2007.
Abstract
Background:
Serum 25-hydroxyvitamin D (25(OH)D) is low in obese adults.
Objective:
To examine serum 25(OH)D in obese (BMI >95th percentile for age) vs. non-obese (BMI = 5th–75th percentile for age) 6–10-year-old African American children and compare their differences in therapeutic response to vitamin D supplementation.
Methods and Procedures:
In an open label non-randomized pre-post comparison 21 obese (OB) and 20 non-obese (non-OB) subjects matched for age, sex, skin color, and pubertal maturation were treated with 400 IU of vitamin D3 daily for 1 month. Serum 25(OH)D, 1,25-dihydroxyvitamin D (1,25(OH)2D), parathyroid hormone (PTH), leptin, and markers of bone turnover (serum bone-specific alkaline phosphatase (BSAP), osteocalcin (OC), and urine n -telopeptide cross-links of type 1 collagen (urine NTX)) were measured. Vitamin D deficiency was defined as serum 25(OH)D 
20 ng/ml and insufficiency as 21–29 ng/ml respectively.
Results:
Vitamin D deficiency occurred in 12/21 (57%) OB vs. 8/20 (40%) non-OB at baseline (P = 0.35) and persisted in 5/21 (24%) OB vs. 2/18 (11%) non-OB (P = 0.42) after treatment. When the cohort was stratified by the baseline levels of 25(OH)D, there were differences in the response to treatment in the obese and non-obese cohorts.
Discussion:
Vitamin D deficiency was common among OB and non-OB preadolescent African American children, and 400 IU of vitamin D3 (2
the recommended adequate intake) daily for 1 month was inadequate to raise their blood levels of 25(OH)D to 
30 ng/ml.
