  Let $L/K$ be a Galois extension of number fields and let
$G=\mathrm{Gal}(L/K)$. We show that under certain hypotheses on $G$, for a
fixed prime number $p$, Leopoldt's conjecture at $p$ for certain proper
intermediate fields of $L/K$ implies Leopoldt's conjecture at $p$ for $L$. We
also obtain relations between the Leopoldt defects of intermediate extensions
of $L/K$. By applying a result of Buchmann and Sands together with an explicit
description of units and a special case of the above results, we show that
given any finite set of prime numbers $\mathcal{P}$, there exists an infinite
family $\mathcal{F}$ of totally real $S_{3}$-extensions of $\mathbb{Q}$ such
that Leopoldt's conjecture for $F$ at $p$ holds for every $F \in \mathcal{F}$
and $p \in \mathcal{P}$.
