Exploring Vitamin Supplementation and Disease

Jun 13 2014

Exploring Vitamin Supplementation and Disease

vitaminVitamins are essential to growth and development, especially for children. Unfortunately, many pediatric diseases are associated with suboptimal levels of vitamins and vitamin deficiencies. One Children’s Hospital investigator, Kelly A. Dougherty, PhD, works to better understand the connection between childhood diseases and vitamin levels. Dr. Dougherty recently received an award from the NIH that will support her investigation of vitamin A supplementation and sickle cell disease. Additionally, she also contributed to an article in the Journal of the Pediatric Infectious Diseases Society that examined vitamin D deficiency in children with HIV.

The NIH award will support Dr. Dougherty’s investigation of vitamin A deficiency in children with type SS sickle cell disease (SCD). In addition to being most famous for anemia and episodes of pain, SCD is also linked to suboptimal levels of vitamin A, which can lead to poor growth and hospitalizations. Vitamin A deficiency is associated with vision problems and a decreased ability to fight infections.

Dr. Dougherty’s project builds on research led by CHOP’s Virginia Stallings, MD, published in The American Journal of Clinical Nutrition in 2012. That study sought to determine whether supplementation could optimize vitamin A status in children with type SS sickle cell disease. However, despite 12 months of study, the investigators found vitamin A supplementation at doses recommended for healthy children did not improve the patients’ serum retinol levels. For her new investigation, Dr. Dougherty will study the safety and efficacy of much higher doses of vitamin A — 2500 and 5000 international units (IU) per day, versus the 2012 study’s ceiling of 2000 IU. The researchers plan to test what effect these higher doses of vitamin A have on children with SCD compared to healthy subjects.

The big question posed by the 2012 American Journal of Clinical Nutrition study is where the vitamin A went — in other words, did the patients eliminate it via urination or a bowel movement, or was it still in their bodies, or sequestered in the liver? — so with her new project Dr. Dougherty is looking to get a sense of the patients’ “total body vitamin a status,” she said.

From SCD to HIV

The Journal of the Pediatric Infectious Diseases Society (JPIDS) study, meanwhile, explores a different vitamin in a different patient population. Namely, vitamin D in children with HIV. While HIV-related research is a newer area for Dr. Dougherty, the HIV research makes sense as she is “interested in physical activity and nutrition issues in children with chronic diseases,” and “children with HIV have been shown to be deficient with vitamin D,” Dr. Dougherty said.

With this investigation, the researchers sought to determine the vitamin D dose needed to bring HIV patients with suboptimal levels of vitamin D up to normal levels. Suboptimal vitamin D “is common in HIV infected individuals and associated with increased risk of HIV disease severity and death,” the authors note. In general, vitamin D deficiency is associated with the possibility of developing rickets in children or osteoporosis in adults.

44 subjects aged 8.3 to 24.7 years old — 57 percent of whom had behaviorally acquired HIV and 43 percent of whom had perinatally acquired HIV — were given either vitamin D supplements at 4,000 or 7,000 IU/day and assessed at 6 and 12 weeks. The researchers found a dose of 7,000 IU/day was “safe and effective in children and young adults with HIV.”

Overall, the goal of all of Dr. Dougherty’s work is to find ways to improve outcomes and quality of life for pediatric patients suffering from chronic disease, she said.

To learn more about AIDS/HIV, sickle cell disease research, clinical nutrition, and healthy diets, see The Children’s Hospital of Philadelphia website.