About the study
Vitamin D deficiency (VDD) is very common among African American adolescents and adults in
the US, ten times higher than is seen in Caucasians. VDD is also quite common in sickle cell
disease (SCD). Both VDD and SCD can cause chronic pain, compression fractures, and muscle
weakness. The investigators believe VDD may contribute to poor musculoskeletal health and
chronic pain seen in pediatric SCD. In this study, the investigators aim to show that
children and adolescents with SCD and chronic pain have lower levels of vitamin D compared to
those without chronic pain. The investigators also aim to determine the clinical
characteristics in SCD patients related to their vitamin D status.
About 60 subjects (7 to 21 years old) will be enrolled on this study, 30 with chronic pain
and 30 without chronic pain. The investigators will assess baseline characteristics including
vitamin D levels, bone turnover rates (measured by C telopeptide blood levels [CTx]), markers
of inflammation and oxidative stress levels in blood, baseline hemoglobin and other
laboratory parameters, presence of abnormal bones on chest x-ray, pulmonary function, opioid
analgesic use, overall muscle strength, quality of life and depression.
To evaluate the impact of vitamin D replacement on these baseline characteristics, the
investigators will randomize subjects to receive either placebo or high dose vitamin D for 6
weeks after which time the investigators will evaluate overall vitamin D status, muscle and
bone health, depression, quality of life, pain status and use of opioid pain medications,
inflammation and oxidative status comparing before and after treatment with high dose vitamin
D. The investigators will give-at no cost to subjects-a daily supplement that will provide
the recommended daily allowance of calcium and vitamin D that contains 500mg Calcium and
200IU vitamin D to subjects throughout the study period. Subjects will be in the study for 7
months and have five to six study visits.