**Note: All laboratory testing requires an authorizing physician. DHA Laboratory offers a patient direct program that partners you with an authorizing physician. If you have any additional questions regarding the availability of testing, please contact our laboratory by telephone or email.**
Differential diagnosis of hypervitaminosis A. A combination of a low serum carotene level and a low vitamin A suggests inadequate vitamin A nutrition.
Patient Preparation: Patient should fast for 12 hours and abstain from alcohol for 24 hours prior to collection. For those who are younger than six months, draw prior to next feeding. Blood should be collected before breakfast in the morning and prior to any medication.