If you simpy have light from directly above, it will create shadows on your face. Is that acceptable to you? I think if you have a large mirror that reflects the light from the downlights you can get away with it.

For makeup I have a moveable LED mirror similar to this in white that I purchased on Amazon.

Yes, you will need/want a dedicated lighted makeup mirror. I'm still using the one I've had for 20 years because I love it and I don't care if it "matches" the design of the bathroom. I can always stick it in a closet when the Style Judges show up. ;>)

Seriously, you will want separate lighting for makeup, in addition to ceiling lighting. I have cans all over the ceiling plus pendants over the vanity and still use my mirror.

You don't need a dedicated makeup mirror, but you do want a serious amount of light from in front of you (either on the sides or in front above, like over the mirror) for any close business, from teeth to makeup. I would say no less than the equivalent of 150W of incandescent light (and 200 with a dimmer is even better). Cans won't cut it, but you could do a light bar to keep things sleek.

Shiloh LED Vanity Fixture, Polished Chrome, 28" · More Info

Beam LED 22" Linear LED Bath, Brushed Nickel · More Info

I have an LED light bar just like the ones pictured above in another bathroom and it does light things up, even with 10' ceilings. However, I have a big window above the dropped down vanity in my master bath where I do makeup so no place to put a fixture (which is why I used pendants from the ceiling) and that LED light bar can't flip to magnification or adjust from "day" to "home" to "office" to "night" like my ancient makeup mirror does, lol. An LED on a dimmer could be just right for people with better eyes than mine.