RDA

• The first is the Recommended Dietary Allowance (RDA), which was formulated in 1968. These guidelines are the minimums needed to avoid diseases such as scurvy.
  
  

RDI and RDV

• The RDA was used to determine the Reference (or Recommended) Daily Intake (RDI). The Recommended Daily Value (RDV), which is used on food labeling, was based on this updated RDI.
  
  

Dietary Reference Intake

• The second guideline is the Dietary Reference Intake, or DRI system, which was formulated in 1997. This guideline has been adopted by the United States Department of Agriculture (USDA).
  
  

DRI

• The Dietary Referral Intake system accounts for age and gender, as well as giving recommendations for pregnant and lactating women.
  
  

Considerations

• Most people can meet all their nutritional allowances by following a varied diet modeled on the food pyramid. Supplements may be needed for pregnant and lactating women and vegetarians, or as advised by your doctor.