My partner takes A
A men's over 50 multi that has like 30 different vitamins and minerals in it. Some high doses and others negligible.

He is under the impression that taking a multi is safer and cheaper thanbuying individual vitamins.

I take;

1000mcg methyl cobalamin 4-5 times a week
600 mg Biotin daily
50 mg R- lipoic acid daily
Iron tablet daily
2000 iu vitamin D daily
2 Flaxseed oil capsules daily
99 mcg potassium gluconate x twice a day
Magnesium chelate capsule at bedtime

I am deficient in iron and vitamin D.
I take Biotin because my hair started to fallout from hyperthyroid and at home dye job.

Anyways, my question is how do vitamin manufacturers get 30 vitamins and minerals in one tablet?? How does it work?

Is it unsafe to take individual vitamins like I do? Is it ok to take all the above vitamins in one sitting or do I need to split it up?

Thank you