NHANES

National Health and Nutrition Examination Survey, a survey conducted periodically by the National Center for Health Statistics, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services

NHIS

National Health Interview Survey, a survey conducted periodically by the National Center for Health Statistics, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services

NOAEL

No-observed-adverse-effect level; the highest intake (or experimental dose) of a nutrient at which no adverse effect has been observed.

NRC

National Research Council, the organizational arm of the National Academies

NTD

Neural tube defect

4-PA

4-Pyridoxic acid

pABG

p-Aminobenzoylglutamate

PARP

Poly-ADP-ribose polymerase

PGA

Pteroylglutamic acid

PL

Pyridoxal

PLP

Pyridoxal phosphate

PM

Pyridoxamine

PMP

Pyridoxamine phosphate

PN

Pyridoxine

PNP

Pyridoxine phosphate

RDA

Recommended Dietary Allowance

Risk

Within the context of nutrient toxicity, the probability or likelihood that some adverse effect will result from a specified excess intake of a nutrient.

Risk assessment

An organized framework for evaluating scientific information that has as its objective a characterization of the nature and likelihood of harm resulting from excess human exposure to an environmental agent (in this case, a dietary nutrient). It includes the development of both qualitative and quantitative expressions of risk. The process of risk assessment can be divided into four major steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization.