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Vitamin C, also known as ascorbic acid, is an essential nutrient. This means that it is not stored in tissues and must be consumed regularly through the diet. When vitamin C is consumed in food, it is absorbed and moves freely through the body and cells to perform its many functions.

The body requires vitamin C to synthesize several chemical compounds involved in building tissues and cellular communication. These compounds include:

• Collagen. Connective proteins that provide the structural framework for building and maintaining tissues. Collagen helps make some tissues elastic (e.g., skin, blood vessels, tendons, ligaments) and others rigid (e.g., teeth, bones). Scar tissue is also made of collagen, which allows wounds to heal.
  
  
• Carnitine. Chemical responsible for transporting fatty acids within cells to the mitochondria of the cell, where they are metabolized for energy.
  
  
• Serotonin and norepinephrine. Neurotransmitters critical to stress response. They are also associated with behavior and mood.
  
  
• Thyroxin. Hormone involved in regulating the metabolic rate. In times of stress, additional thyroxin is released to increase the amount of energy available.
  
• Hemoglobin. Protein in red blood cells that transports oxygen. Vitamin C enhances iron absorption, which is necessary to synthesize hemoglobin.

In addition to helping the body synthesize compounds, vitamin C protects cells from the effects of free radicals. These highly reactive chemicals can damage DNA and proteins, which alters the function of cells. Vitamin C functions as an antioxidant, which reduces free radical reactivity and their ability to damage human tissues.

The U.S. National Academy of Sciences has established dietary reference intakes (DRIs) for vitamin C. DRIs provide the daily intake of vitamin C necessary to support a healthy body – based on age and gender (including whether women are pregnant or breastfeeding). Tolerable upper intake levels (UL) were also determined. Patients who consume more than the UL for vitamin C increase potential health risks. These recommendations are measured in milligrams per day (mg/day).

Vitamin C DRIs

*Adequate intakes are provided for infants. These values are the average amount consumed by each age group.

Cigarette smoke and chewing tobacco produce oxidants, which deplete the body’s stores of vitamin C. Patients who use these products should add 35 mg to the daily recommendation. Additional vitamin C is also suggested for those who are routinely exposed to secondhand smoke.