In a healthy adult who runs regularly, is routine multivitamin supplementation indicated, and if so, what specific formulation and dosing are recommended?

Multivitamin Supplementation for Healthy Runners

For healthy adults who run regularly, routine multivitamin supplementation is not indicated—focus instead on obtaining nutrients through a balanced diet rich in fruits, vegetables, whole grains, lean proteins, and dairy. 1, 2

Evidence-Based Rationale

Primary Recommendation: Food First Approach

• There is no clear evidence of benefit from vitamin or mineral supplementation in healthy individuals without underlying deficiencies. 1
• The American Diabetes Association explicitly states that most healthy adults can obtain adequate vitamins and minerals through diet alone without supplementation. 2
• Elite football (soccer) nutritional guidelines emphasize a "food first" approach, with supplements used only to meet specific health or performance objectives that cannot be achieved through diet. 1
• Healthy eating patterns featuring fruits, vegetables, whole grains, and lean proteins provide synergistic benefits from bioactive compounds that cannot be replicated by isolated supplements. 3, 4

When Multivitamins May Be Considered

If you choose to take a multivitamin despite adequate dietary intake, select one providing approximately 100% of the RDA for most nutrients—not megadoses. 2

Multivitamin supplementation may be reasonable only in these specific circumstances:

• Calorie-restricted diets (<1,500 kcal/day) during weight loss phases. 1, 2
• Strict vegetarians who may require B12, iron, zinc, and calcium supplementation. 1, 2
• Documented dietary inadequacy confirmed by a registered dietitian nutritionist. 1

Specific Micronutrient Considerations for Runners

Vitamin D

• Recommended intake: 600 IU/day for adults under 70 years. 2
• Vitamin D status should be optimized, with levels maintained between 32-50 ng/mL if deficiency is documented. 1
• Higher doses may be needed if deficient, but supplementation should be based on measured serum 25(OH)D levels, not routine prophylaxis. 1

Calcium

• Recommended intake: 1,000 mg/day for adults under 50 years; 1,200 mg/day for adults over 50 years. 2
• Calcium-rich foods should be prioritized, with optimal intake between 1,000-1,300 mg/day from dietary sources. 1
• Supplementation with calcium citrate (600 mg/day) should only be considered if dietary intake is insufficient. 1

Iron

• Recommended intake: 8 mg/day for men; 18 mg/day for premenopausal women. 2
• Routine iron supplementation can do more harm than good, and the risk of iron toxicity is real. 1
• Iron supplementation should only be prescribed for documented deficiency based on laboratory testing (ferritin, complete blood count). 1
• Athletes who self-prescribe supplements are often those least likely to require them. 1

B Vitamins

• Recommended intake: B6 1.3 mg/day, B12 2.4 µg/day, Folic acid 400 µg/day. 2
• No evidence supports routine B-vitamin supplementation in healthy runners without documented deficiency. 1

Performance Supplements: Limited Evidence

• Caffeine and creatine have the strongest evidence for performance enhancement, but even these should be trialed in training before competition. 1
• Beta-alanine and nitrate have weaker evidence for football-specific performance benefits. 1
• Most performance supplements have not undergone sport-specific testing in elite athletes and show large inter-individual variability in response. 1

Critical Pitfalls to Avoid

• Do not routinely supplement antioxidants (vitamins E, C, carotene)—lack of efficacy and concern for long-term safety. 1
• Do not supplement chromium—benefit has not been clearly demonstrated. 1
• Do not exceed upper safety limits: Vitamin E >1,000 mg/day increases hemorrhagic risk; Vitamin A >3,000 µg/day has teratogenic risk; Vitamin D >4,000 IU/day without supervision. 2
• Do not assume multivitamin use guarantees adequate status—absorption depends on individual factors including gut health and dietary fat intake. 5
• Do not purchase supplements independently—use only those provided or recommended by a sports nutritionist or team physician to ensure quality and avoid contamination. 1

Practical Algorithm

1. Assess dietary intake through 3-day food logs reviewed by a registered dietitian nutritionist. 1
2. If dietary intake meets RDA for all nutrients, no supplementation is needed. 1, 2
3. If specific deficiencies are suspected (fatigue, poor recovery, recurrent illness), test specific micronutrients (25(OH)D, ferritin, B12) before supplementing. 1
4. If supplementation is chosen despite adequate diet, use a standard multivitamin providing ~100% RDA, not megadoses. 2
5. Monitor for adverse effects and reassess need every 3-6 months. 1