I haven't been tested for Vitamin D deficiency. But... and I'm very easily wrong here, but... wouldn't taking a multi vitamin make this testing unnecessary for

I haven't been tested for Vitamin D deficiency. But... and I'm very easily wrong here, but... wouldn't taking a multi vitamin make this testing unnecessary for the most part? I mean, don't get me wrong, it's always best to test, but diminishing returns and all, wouldn't most people most of the time be fine with just taking one?