Newly Diagnosed Children with Cancer Have Lower 25-Vitamin D Levels than Their Cancer-Free Peers: A Comparison across Age, Race, and Sex.

Children with cancer have a greater risk for vitamin D concerns because of compromised health before diagnosis, the disease itself, and treatments for the cancer. This IRB-approved retrospective, matched case−control study of children with and without cancer included three race categories: black, other, and Caucasian. This is the first study to directly compare serum 25-hydroxy vitamin D (25(OH)D) levels and status in newly diagnosed pediatric cancer patients with age-, sex-, and race-matched cancer-free children from the same geographic region of the US, all of whom are free from other conditions that negatively impact 25(OH)D levels. Univariable and multivariable ordinal logistic regressions were performed. In the 544 children (mean age of 8.5 years, 53% female), there were 136 newly diagnosed children with cancer and 408 matched non-cancer controls. Serum 25(OH)D levels at cancer diagnosis were lower (22.4 ng/mL) than in controls (30.1 ng/mL; p < 0.0001). Differences persisted across race (p < 0.001) and age (p < 0.001), but not sex. Older children exhibited lower 25(OH)D levels. Only 18.4% of the children with cancer had sufficient levels. Black children with cancer had the greatest rate of deficiency (39%). Race differences were evident: children of color (other and black) displayed higher levels of insufficiency; black children were most deficient.