I'm using Zabbix as my Linux monitoring solution.
It shows MySQL - The buffer pool utilization is less than 50% in the last 5 minutes. This means that there is a lot of unused RAM allocated for the buffer pool, which you can easily reallocate at the moment as a warning.
should I worry about this do?
How to overcome this issue?
You have configured your MySQL with more RAM than needed, check your configuration (my.cnf, my.cnf.d and so on) for the innodb_buffer_pool_size and lower it.
How much lower? It depends on the effective usage, you can see it on your Zabbix graphs.
Don't forget to restart the mysql service!