3 times fit bodies should supplement

Certain nutrients can help you through tough training periods.

The idea of when—and if—you should supplement is hotly contested. Research in the Journal of the American College of Cardiology shows that vitamin supplementation largely does not improve heart health or longevity. Still, it depends. Your health may be best served by taking particular vitamins and minerals during certain times of your life, especially in these three instances. (As always, talk to your doctor before taking any new supplements.)

A heavy training season
: If you’re working towards a marathon or some other exhaustive physical feat, an omega 3 supplement can offset inflammation, research shows.

Pregnancy: Before trying to conceive, 0.4 milligrams of folic acid a day can help prevent neural tube defects, says Nicole Avena, Ph.D., assistant professor of neuroscience at Mount Sinai School of Medicine in New York City. A prenatal vitamin will deliver the folic acid you need, but look for one with 18 milligrams of iron, too, to reduce risk of anemia. If morning sickness hits, settle your stomach with 1.9 milligrams of B6, she says.

Diet changes: If you’ve gone vegan or cut way back on animal products, buffer some potential deficiencies by taking a B12 supplement, suggests Ryan Andrews, R.D., author of A Guide to Plant-Based Eating. B12 is only found in animal products and fortified sources (like nutritional yeast). Taking vitamin D (especially D3), vital for immune and bone health, may also be important, as many rely on dairy to provide the vitamin.