Remember, there is no substitute for a healthy diet. And it is always best to talk to a nutritionist or your GP before taking anything, especially if you are on other meds, pregnant or trying to get pregnant.
There is a good list of supplements’ safety if pregnant here.
You’d have to really go some to do yourself any harm with supplements but don’t underestimate them; they are powerful and can be life-changing.
Check the free resources below for a summary of nutrient advisory statements and possible interactions with foods and other meds.
If you need more help, please talk to your health professional for advice.
Cautions & Contraindications of Nutrients
There is also a good drug-supplement checker here at Medscape. And another for more US drugs here.