Vitamin C - Bioavailability

Introduction

This section outlines factors that influence the absorption, storage and excretion of Vitamin C.

ORAL ABSORPTION

 Vitamin C is absorbed by the Intestines.

 The amount of Vitamin C that is absorbed depends upon the amount of Vitamin C ingested:

 At low doses (less than 30 mg), up to 100% of Vitamin C is absorbed.

 At typical dietary intake (30 – 200 mg per day), 70% to 90% of Vitamin C is absorbed.  80% of a 100 mg dose is absorbed.  72% of a 200 mg dose is absorbed.

 At a dosage of 1,000 – 1,500 mg, approximately 50% of Vitamin C is absorbed.

 At a dosage of 12,000 mg, approximately 16% of Vitamin C is absorbed.

 The maximum amount of Vitamin C that can be absorbed at once is estimated to be 3,000 mg.