Supplements that can help women runners 40+

Supplements are supplements — they add to a good diet, they do not replace one. But for women 40+, a few are genuinely worth considering.

Always speak to your GP before starting any supplement, especially if you take medication or have a health condition.

The evidence-based shortlist:

1. Vitamin D

• Why: Essential for calcium absorption, bone health, immune function, and muscle function. Deficiency is extremely common, especially in winter or if you spend most of your time indoors.
• Dose: 10–25 micrograms (400–1000 IU) daily is a common maintenance dose. Your GP can test your levels and advise.
• Best taken: With a meal containing fat, as vitamin D is fat-soluble.

2. Omega-3 (EPA/DHA)

• Why: Anti-inflammatory, supports joint health, brain function, and cardiovascular health. Particularly relevant as oestrogen decline increases systemic inflammation.
• Source: Oily fish (salmon, mackerel, sardines) 2–3 times per week, or a quality fish oil / algae oil supplement.
• Dose: 250–500mg combined EPA/DHA daily.

3. Calcium

• Why: Bone density. Women over 40 need 1,000–1,200mg daily. If your diet is low in dairy or fortified foods, a supplement can bridge the gap.
• Best taken: In smaller doses (500mg) with food, as absorption decreases with larger amounts.

4. Iron (only if deficient)

• Why: Iron deficiency causes fatigue, poor recovery, and reduced exercise capacity. It is common in women due to menstruation and is worth checking.
• Important: Do not supplement iron without a blood test. Excess iron is harmful. Ask your GP for a ferritin test.

5. Magnesium

• Why: Supports muscle function, sleep quality, and energy production. Many women find magnesium helpful for sleep and muscle cramps, particularly in perimenopause.
• Dose: 200–400mg, ideally in the evening. Magnesium glycinate is well-tolerated for sleep.

6. Protein powder (convenience, not necessity)

• Why: Not a magic supplement, but a practical way to hit protein targets — especially post-run when you do not feel like eating a full meal.
• Choose: Whey isolate or a complete plant-based blend. Look for one with minimal added sugar.

What to skip:

• BCAAs: If you eat enough protein, they are redundant.
• Fat burners: No evidence they work, and they can be harmful.
• Collagen: Some emerging evidence for joint and tendon health, but the research is still early. Not essential.

The bottom line: A blood test from your GP tells you far more than any supplement advert. Test before you supplement — and focus on food first.