  Given a proper total $k$-coloring $c:V(G)\cup E(G)\to\{1,2,\ldots,k\}$ of a
graph $G$, we define the value of a vertex $v$ to be $c(v) + \sum_{uv \in E(G)}
c(uv)$. The smallest integer $k$ such that $G$ has a proper total $k$-coloring
whose values form a proper coloring is the neighbor sum distinguishing total
chromatic number of $G$, $\chi"_{\Sigma}(G)$. Pil\'sniak and Wo\'zniak (2013)
conjectured that $\chi"_{\Sigma}(G)\leq \Delta(G)+3$ for any simple graph with
maximum degree $\Delta(G)$. In this paper, we prove this bound to be
asymptotically correct by showing that $\chi"_{\Sigma}(G)\leq
\Delta(G)(1+o(1))$. The main idea of our argument relies on Przyby{\l}o's proof
(2014) regarding neighbor sum distinguishing edge-colorings.
