does i not take my vitamins before a fasting blood test
1 A period of 8 to 12 hours of fasting will be necessary before the test; eating or drinking during the fasting period will cause the results to be inaccurate. 2  You will not be able to take any vitamin or mineral supplements within 24 hours of testing.asting blood tests include triglyceride and cholesterol tests, glucose tests, and vitamin level tests which require fasting for up to 12 hours before testing for result accuracy. Blood testing is done to check the blood for abnormalities, including high cholesterol and glucose levels.