In addition to its role in bone metabolism, vitamin D has important immunomodulatory and antineoplastic effects. Patients on home parenteral nutrition (HPN) receive most of their vitamin D from intravenous (IV) supplementation. Vitamin D deficiency is common in the general population, and the adequacy of vitamin D supplementation in HPN patients is unclear. The purpose of this study is to determine the vitamin D status of patients on HPN.
Consecutive patients seen in a regional home nutrition program had their oral and IV vitamin D intakes determined. Plasma 25-hydroxyvitamin D levels were measured in all patients. Intake of calcium, magnesium, and phosphate were also determined.
The mean 25-hydroxyvitamin D level in 22 patients receiving HPN for a mean of 33.5 months (range, 1-177) was 42 nmol/L. Vitamin D deficiency was present in 15 (68%) patients and vitamin D insufficiency in 6 (27%) patients. The mean dietary vitamin D intake was 79.5 IU per day, while the mean IV supplementation was 166 IU per day.
In this study of a regional Canadian HPN program, there was a high prevalence of vitamin D deficiency/insufficiency affecting virtually all patients. All patients receiving HPN should be supplemented with vitamin D and have their 25-hydroxyvitamin D levels monitored. Further studies are required to determine optimal methods and dosing of vitamin D replacement using oral supplements or ultraviolet light therapy.