What Is a Vitamin? Towards a Contemporary Definition

Area of Science:

• Nutritional Science
• Biochemistry
• Public Health

Background:

• Vitamins have evolved from deficiency preventatives to crucial long-term health nutrients.
• Current definitions lack clarity in distinguishing vitamins from other bioactive compounds.
• Nutritional requirements for vitamins are complex and not fully captured by existing definitions.

Purpose of the Study:

• To review the historical evolution of vitamin definitions.
• To identify limitations in current vitamin definitions.
• To propose a contemporary, physiologically informed definition of vitamins.

Main Methods:

• Historical review of vitamin definitions.
• Analysis of current scientific literature on vitamins.
• Development of a new definition based on physiological understanding.

Main Results:

• Existing definitions are insufficient and do not encompass the full role of vitamins.
• A new definition is proposed that moves beyond classical deficiency prevention.
• The proposed definition incorporates conditional essentiality.

Conclusions:

• A contemporary definition of vitamins is needed to reflect their complex roles.
• The concept of conditional essentiality helps distinguish vitamins from other bioactive substances.
• Variable dietary requirements under different conditions are key to understanding vitamin needs.