Which of the following statements is false?
1) Water soluble vitamins require bile for efficient absorption.
2) Niacin is incorporated into a REDOX coenzyme.
3) Tetrahydrofolate is a CO₂ carrier/donor in purine synthesis.
4) Retinoic acid is a maintenance hormone for epithelial cell layers.
5) Thiamine is used in several oxidative decarboxylation reactions.
6) Pernicious anemia occurs when the intestines cannot properly absorb vitamin E.