Vitamin labels may be wrong.

The amounts of Vitamin D present in supplements sold over the counter often bear little resemblance to the descriptions on the bottle labels, a new study concludes.

Researchers used high-performance liquid chromatography to analyze pills in 55 bottles of vitamin D bought at five stores in Portland, Ore. Their results were published online last week in JAMA Internal Medicine.

Researchers conduct a __________ hypothesis test?

Select one:

a. Two-tailed

b. Directional

c. T

d. Correlational

e. One-tailed