You should always try to use the established recommended daily allowance when in doubt.

Here is all you should need for appropriate referencing material.

***Keep in mind that this is what they recommend to sustain the most necessary of biological functions that pertain to living. Dosages are subject to variences as well as personal discretion.

DRI TABLE

As long as you are taking Vitamin K2 with your D3, overdose is virtually impossible. You have to be deficient in K2 in order to overdose on D3. With the zinc, be sure you are not deficient in copper, and if you are, use a zinc supplement that includes it. You also need to be sure you have good levels of melatonin going at night. Zinc needs the correct melatonin levels to be effective. If your levels are good, you should be good sticking with a low-dose of the zinc, because your body will actually be able to use it all. If you are a night owl, sleep with ambient light around, or consume fructose after 2-3PM, your melatonin levels may not be timing themselves right and your cortisol won't drop at night as it should. Zinc and melatonin work synergistically, and low levels of one can indicate low levels of another. If your sleep is not rock-solid, you could try supplementing with a sublingual melatonin at night, or use tryptophan to naturally boost your levels.

Sometimes overdosing is not the only probelm. Many people don't know this, but taking different vitamins pills can make your liver heat up which leads to illness, but you can keep yourself from falling ill if you get blood tests every four month, especially LFT (Liver function test) to stay healthy. Cheers)