It's recommended that iodine/iodide (1,000 mcg+; add 200 mcg L-selenomethionine when taking higher amounts) and vitamin E (2 IU/g) are added when supplementing PUFAs. Iodide/Iodine binds with double bonds making the structure less prone to oxidation and vitamin E counters oxidation.

Most don't get enough vitamin D (and magnesium) even if eating well. 40-60 ng/mL 25(OH)D is a commonly preferred range.