Hyperlipidemias, and notably hypercholesterolemia, represent important
risk factors for atherosclerotic vascular disease. The enzymatic inhi
bitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, a selective
and specific key enzyme involved in endogenous cholesterol synthesis,
cause a significant mean reduction in low-density lipoprotein (LDL) c
holesterol, both in familial and nonfamilial hypercholesterolemic form
s. It has been hypothesized that these compounds might interfere with
vitamin D endogenous synthesis secondarily to their effects on cholest
erol. To verify this hypothesis, we studied 14 hypercholesterolemic pa
tients treated as follows: 4 weeks of low-lipid, fiber-rich diet follo
wed by 8 weeks of pravastatin treatment at the oral evening dose of 20
mg/d and by a 1-month washout period. No significant changes in serum
calcium, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D were notice
d; on the contrary, significant (P < 0.01) reductions in total cholest
erol and LDL cholesterol and a significant (P < 0.05) increase in high
-density lipoprotein cholesterol were observed. After the final 1-mont
h washout period, all values returned to baseline levels. In conclusio
n, our study confirms the clinical efficacy of pravastatin on lipid fr
actions and demonstrates the absence of any interference on the circul
ating levels of the main vitamin D metabolites.