I guess you would have to consume certain types of vitamin products, fatty acids, calcium supplements and so forth. I am not so sure that a vegan diet gives a person enough minerals and vitamins for their body. Does a plant-based diet meet every nutrient needs? I am not sure that it does. Therefore, you think you may need to have nutrients from supplements. I wonder whether this is a good idea. Check whether you can get enough minerals and vitamins from plant-based food items. I think that maybe a safer option for you.
 
If you must consume supplements, take precautions, such as reading the labels of the products. You may have to eat certain supplements with food items. Even I have done so as per my doctor’s recommendation. On the other hand, other dietary supplements may have to be consumed a few hours before or after you have food.