1) https://nutritionfacts.org/optimum-nutrient-recommendations/ https://nutritionfacts.org/optimum-nutrient-recommendations/ According to this source, dependin

1) https://nutritionfacts.org/optimum-nutrient-recommendations/ https://nutritionfacts.org/optimum-nutrient-recommendations/ According to this source, depending on your location , diet, age, and gender, you may need to worry about: Vitamin B12 Vitamin D Calcium Omega-3 Fatty Acids Iodine Iron Selenium You are probably getting enough of everything else from food. 2) https://www.usp.org/verification-services/verified-mark https://www.usp.org/verification-services/verified-mark According to this organization, their verification mark means: Contains the ingredients listed on the label, in the declared potency and amounts Does not contain harmful levels of specified contaminants Will break down and release into the body within a specified amount of time Has been made according to FDA current Good Manufacturing Practices using sanitary and well-controlled procedures The UPC mark means it is what is says it is. It does not mean you need it, or it is good for you.