Objective: Ketogenic diets tend to cause trace mineral deficiencies. Ketonformula is a foumula for a ketogenic diet developed by Meiji Co Ltd in Japan. No reports are available on the trace mineral deficiencies associated with a use of Ketonformula.
Methods: We monitored the serum levels of selenium, zinc and copper as well as the amount of the daily intake of these minerals before and at 6 months after the initiation of the ketogenic diet with Ketonformula in six patients with intractable epilepsy associated with severe motor and intellectual disabilities.
Result: The median serum selenium concentration decreased from 7.0 (range, 6.5-12.3) microg/dl to 6.2 (5.4-10.9) microg/dl as a result of the 6-month-treatment with Ketonformula (p < 0.05, Wilcoxon signed-rank test). The median daily selenium intake decreased from 17.8 (15.0-27.0) microg/day at the baseline to 5.5 (5.0-22.0) microg/day after 6 months on the diet (p < 0.05). The median serum zinc concentration increased slightly (from 66.0 (46.0-84.0) microg/dl to 68.0 (46.0-71.0) microg/dl), but the difference was not significant. The median daily zinc intake, however, significantly decreased from 4.2 (3.7-6.0) mg/day to 2.2 (2.0-3.0) mg/day (p < 0.05). The median serum copper concentration also showed no significant decrease (from 134.5 (119.0-168.0) microg/dl to 126.0 (86.0-183.0) microg/dl). The median daily copper intakes, however, decreased significantly from 0.80 (0.35-1.30) mg/day to 0.30 (0.26-0.40) mg/day (p < 0.05).
Conclusions: The decline of the serum selenium concentrations and daily enteral intakes of selenium, zinc, and copper after 6 months on Ketonformula suggested that patients on this ketogenic formula needs close monitoring as well as supplementation of these trace minerals.