What daily supplements can help prevent illness?

Daily Supplement Recommendations for Illness Prevention

For most healthy adults, routine vitamin and mineral supplementation is not recommended for preventing illness, as there is insufficient evidence of benefit for cardiovascular disease or cancer prevention, and nutrients should come primarily from a balanced diet rich in fruits, vegetables, and whole grains. 1

General Population: What NOT to Take

Avoid β-carotene and vitamin E supplements entirely, as these have been proven ineffective and potentially harmful 1, 2:

• β-carotene increases lung cancer risk in smokers and those with asbestos exposure 1
• Vitamin E provides no net benefit for cardiovascular disease or cancer prevention 1, 2

Multivitamins: Insufficient Evidence

The evidence for multivitamins remains inadequate 1, 3, 2:

• No effect on all-cause mortality across multiple trials 1, 3
• No cardiovascular disease benefit demonstrated 1, 3
• Modest cancer reduction seen only in men (not women) in limited studies, making generalizability questionable 1, 3

Specific Populations That Should Supplement

Women of Childbearing Age

• Folic acid supplementation is essential for neural tube defect prevention 1

Older Adults (Age 65+)

Older adults should consider targeted supplementation due to higher deficiency risk 1, 3:

• Vitamin D: 600 IU (15 μg) daily for fall prevention and bone health 1, 3
• Calcium: at least 1,200 mg daily from diet or supplements 3
• Vitamin B12: 4-6 μg daily due to high prevalence of deficiency 3

Individuals at Risk for Respiratory Infections

Vitamin D supplementation reduces respiratory infection risk, particularly in deficient individuals 4:

• For confirmed deficiency: 2,000 IU/day of vitamin D3, especially during winter 4
• For recurrent deficiency: 4,000-5,000 IU/day for 2 months to achieve blood levels of 40-60 ng/ml 4
• Monitor blood levels when using >2,000 IU/day to ensure efficacy and avoid toxicity 4

Critical Safety Warnings

Fat-Soluble Vitamin Risks

Exercise caution with fat-soluble vitamins (A, D, E, K) as they accumulate over time 1, 3:

• Vitamin A: Moderate doses reduce bone mineral density; high doses are hepatotoxic and teratogenic 1, 3
• Vitamins A and D: Known harms above tolerable upper intake levels 1, 3
• Vitamin D toxicity: Rare but occurs with >10,000 IU daily for extended periods 4

The Evidence-Based Alternative

Instead of supplements, prioritize dietary sources 1:

• A diet rich in fruits, vegetables, whole grains, fat-free and low-fat dairy products, and seafood has been associated with reduced cardiovascular disease and cancer risk 1
• Nutrients from food are superior to supplements for overall health 1

Clinical Decision Algorithm

Follow this approach when patients ask about supplements:

1. Assess dietary intake first - determine if nutrient gaps exist 3
2. Identify specific risk factors: age >65, restrictive diets, malabsorption conditions, medications like proton pump inhibitors 3
3. Screen for deficiencies in at-risk populations before supplementing 4, 3
4. Recommend targeted supplementation only for documented deficiencies or high-risk groups 1, 4, 3
5. Emphasize that supplements do not replace healthy diet 1, 3

Common Pitfalls to Avoid

• Do not recommend multivitamins as "insurance" - insufficient evidence supports this practice 1, 3, 2
• Never recommend β-carotene to smokers - increases lung cancer mortality 1
• Avoid exceeding Recommended Dietary Allowances without specific indication 3
• Do not substitute supplements for dietary improvement - this is the most common error 1