Standard multivitamin supplementation does not improve vitamin D insufficiency after burns

Children suffering severe burns develop progressive vitamin D deficiency because of inability of burned skin to produce normal quantities of vitamin D3 and lack of vitamin D supplementation on discharge. Our study was designed to determine whether a daily supplement of a standard multivitamin tablet containing vitamin D2 400 IU (10 μg) for 6 months would raise serum levels of 25-hydroxyvitamin D [25(OH)D] to normal. We recruited eight burned children, ages 5–18, whose families were deemed reliable by the research staff. These children were given a daily multivitamin tablet in the hospital for 3 months in the presence of a member of the research staff and then given the remainder at home. At 6 months, the subjects returned for measurements of serum levels of 25(OH)D,1,25-dihydroxyvitamin D [1,25(OH)2D], intact parathyroid hormone (iPTH), Ca, P, albumin, and total protein as well as bone mass by dual energy X-ray absorptiometry. Serum 25(OH)D levels were compared to a group of seven age-matched burned children studied at an earlier date without the vitamin supplement but with the same method of determination of 25(OH)D at 6 months post-burn. In addition, the chewable vitamins were analyzed for vitamin D2 content by high performance liquid chromatography. Serum concentration of 25(OH)D was 21 ± 11(SD) ng/ml (sufficient range 30–100) with only one of the eight children having a value in the sufficient range. In comparison, the unsupplemented burn patients had mean serum 25(OH)D level of 16 ± 7, P = 0.33 versus supplemented. Serum levels of 1,25(OH)2D, iPTH, Ca, P, albumin, and total protein were all normal in the supplemented group. Vitamin D2 content of the chewable tablets after being saponified and extracted was 460 ± 20 IU. Bone mineral content of the total body and lumbar spine, as well as lumbar spine bone density, failed to increase as expected in the supplemented group. No correlations were found between serum 25(OH)D levels and age, length of stay, percent body surface area burn or third-degree burn. Supplementation of burned children with a standard multivitamin tablet stated to contain 400 IU of vitamin D2 failed to correct the vitamin D insufficiency.