Iron, vitamin D and calcium

Runners lose more iron, especially women, and bones need vitamin D and calcium: eating enough, and a varied diet, come first.

• Iron: red meat, fish, lentils, beans, tofu, leafy greens; add vitamin C to plant iron, and keep tea and coffee away from meals.
• Unusual tiredness, breathlessness or pale skin can mean low iron: ask your doctor for a blood test (ferritin) before taking any iron.
• Vitamin D: made mainly by sun on the skin; levels drop in winter, and a blood test tells you whether you need a supplement.
• Calcium: about 1,000 mg a day from dairy, fortified plant drinks, tofu, almonds.
• Warning signs of low energy availability (RED-S): missed periods, stress fractures, lasting fatigue, unplanned weight loss. See a doctor.