Homocysteine is a sulfur-based amino acid that is considered a 
risk factor for heart disease.  multivit.sas7bdat contains the results 
of an 8 week intervention trial in which subjects were randomized to 
receive either a daily multi-vitamin or placebo.

    SUPP = 1, multivit
           0, placebo

    BTHC -- homocysteine at baseline
    ATHC -- homocysteine after intervention

    BFOLATE -- folate at baseline
    AFOLATE -- folate after intervention