The requirements of vitamins vary considerably depending upon the nature of the individual consuming them.
- Greater the size of the individual, higher is his/her vitamin needs.
- Young ones require higher quantities of vitamins than elders.
- During ailments, the vitamin requirements are ordinarily enhanced.
- In general, high metabolic activity (such as heavy muscular work, during pregnancy, lactation and in growing children), the vitamin requirement is proportionately high.
The requirement of vitamins may increase under greater metabolism. e.g. Thiamine and other Vitamin B complex are required in high amount in case of greater utilization of carbohydrates.