In the <VirtualHost> section only:

<IfModule mod_rewrite.c>
  #redirect upper case
	RewriteEngine on
  #define "lowercase" function
	RewriteMap    lowercase    int:tolower
  #do not follow existing files or folder
	RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI} !-f
	RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI} !-d
  #check if url contain uppercase
	RewriteCond %{REQUEST_URI} [A-Z]
  #redirect
	RewriteRule ^/(.*)$ /${lowercase:$1} [R=301,L]
</IfModule>