An evaluation of plasma vitamin C concentrations in individuals requiring home parenteral nutrition

Background: Ascorbic acid (VitC) is an essential coenzyme to maintain health, but there are minimal data on the adequacy of VitC supply in patients requiring home parenteral nutrition (HPN). Methods: A prospective pilot study was carried out measuring plasma VitC, serum vitamins A, D and E, and the minerals zinc, copper, selenium and magnesium in 28 adult HPN-dependent (≥6 months) patients. Results: Fifty-seven percent of patients had insufficient VitC status. There was a strong, positive correlation between HPN provision of VitC and plasma VitC concentrations (r_s = 0.663, p = 0.00) with an 83% insufficiency rate below a provision of 800 mg week^–1. There was no association seen between plasma VitC and number of HPN days week^–1 (p = 0.539), number of months on HPN (p = 0.773) or dependency on HPN (86% ± 31% of energy requirements met via HPN (77% ± 23%, p = 0.39). Conclusions: VitC insufficiency is prevalent in HPN-dependent patients. Our data highlight the need for regular monitoring of VitC in those living with type III intestinal failure.