Ninety normal healthy adults were given 0, 8, 20 or 32 g/d olestra for
8 wk as part of a diet that provided 1 +/- 0.2 of the recommended die
tary allowance (RDA) of vitamins, A, D, E and K, folate zinc, calcium
and iron. In addition, a 20 mu g/d supplement of vitamin D was supplie
d. The diet provided 15% of energy from protein, 35% from fat and 55%
from carbohydrate. The purpose of the study was to determine the dose
response of olestra on vitamins D, E and K, carotenoids, vitamin B-12,
folate and zinc. Circulating concentrations of retinol, carotenoids,
tocopherols, 25-hydroxy- and 1,25-dihydroxyvitamin D metabolites, phyl
loquinone, des-gamma-carboxyprothrombin, prothrombin, folate and hemat
ological parameters were measured biweekly, as were urine concentratio
ns of zinc and gamma-carboxyglutamic acid (Gla). Clinical chemistry, u
rinalysis and vitamin B-12 absorption were measured at wk 0 and 8. Ole
stra reduced serum concentrations of carotenoids, alpha-tocopherol, 25
-hydroxyergocalciferol and phylloquinone in a dose-responsive manner.
Olestra did not affect Gla excretion, plasma des-gamma-carboxyprothrom
bin or prothrombin concentrations, prothrombin time, vitamin B-12 abso
rption, overall vitamin D status or the status of folate or zinc. Labo
ratory evaluations showed no health-related effects of olestra. Subjec
ts in all groups reported common gastrointestinal symptoms such as loo
se stools, fecal urgency and flatulence, which were transient and gene
rally mild to moderate in severity. These symptoms did not affect prot
ocol compliance or the ability to measure the potential for olestra to
affect nutrient availability.