Why you need additional vitamins, any disease, any disability or any other problems?
If you follow good diet patterns ladden with Green vegetables, fruits, milk and plenty of water I dont think you need any thing additional.
Vitamins are prescribed only if there is some sort of assumed benefit to the patient / person for the condition, for general wel being your mental strength is vital.
If you are not averse to non veg foods, then weekly once a plater of fish will do you more good than all the vitamins together.
For pure vegetarians there is always fruits which is more tasty and more variety.
For calcium and vitamin D there is no substitute like natural sunlight.
I hope you got my point, still if you want to take medicines you can take any good reputed company brand available. Dont go the Amway side or any other MLM side, they charge you premium but dont deliver that much.
If you take overdose of vitamins, excess will be going down the drain via urine and stool, if your urine smells same as medicine and also turns extremely yellow that means your storage of vitamins is full you need to reduce the dose or frequency. and then only take the maintainance dosage.