Choline daily adequate intake for men, women and pregnancy, best food sources, deficiency and liver effects, the 3,500 mg upper limit and supplement forms. Based on NIH.

Vitamin B6 daily needs, food sources, deficiency signs, nerve damage from too much, 100 mg upper limit, and medicine interactions. Based on NIH guidance.

Selenium daily needs, food sources including Brazil nuts, signs of too much selenium, the 400 mcg upper limit and who is at risk of low intake. Based on NIH.

Vitamin K daily needs, best food sources, deficiency signs, who is at risk and why warfarin users must keep intake consistent. Based on NIH guidance.

Vitamin E explained: daily needs, food sources, deficiency causes, upper limit, supplement risks and interactions with blood thinners, based on NIH guidance.

Vitamin A explained: daily needs, food sources, deficiency signs, upper limits, why high-dose supplements are unsafe in pregnancy and medicine interactions, per NIH.

Potassium explained: daily adequate intake, best food sources, signs of low potassium, who is at risk of high levels, salt substitutes and medicine interactions, per NIH.

Omega-3 fatty acids explained: ALA, EPA and DHA, food sources, daily amounts, heart and pregnancy advice, supplement safety and interactions, based on NIH guidance.

Vitamin C explained: how much you need daily, best food sources, deficiency signs, who is at risk, the safe upper limit and interactions, based on NIH guidance.

Magnesium explained: how much you need each day, best food sources, deficiency signs, who is at risk, supplement upper limit and medicine interactions, per NIH guidance.