Supplement Recommendations for Generally Healthy Adults
For generally healthy adults without underlying deficiencies, routine vitamin and mineral supplementation is not recommended, as there is no clear evidence of benefit for disease prevention or health outcomes. 1
General Principles for Healthy Adults
No routine supplementation is advised for individuals eating a balanced diet without documented nutritional deficiencies, as the evidence does not support benefits for cardiovascular disease prevention, cancer prevention, or mortality reduction 1
Antioxidant supplements (vitamins E, C, carotene) should be avoided due to uncertainties about long-term safety and lack of proven efficacy, with some evidence suggesting potential harm 1
Herbal preparations are not recommended because commercially available products lack standardization, vary greatly in active ingredient content, and have potential for medication interactions without proven long-term benefit 1
Specific Populations Requiring Supplementation
Women of Reproductive Age
- Folic acid supplementation is recommended for prevention of neural tube defects in pregnancy 1
Older Adults (≥65 years)
- Calcium 1,200-1,500 mg daily is recommended for bone health and osteoporosis prevention 1, 2
- Vitamin D 2,000-4,000 IU daily should be taken concurrently with calcium to maintain adequate serum levels and support bone health 3, 2
- Calcium citrate is preferred over calcium carbonate, especially if taking acid-reducing medications, and doses should be divided (no more than 600 mg at a time, separated by 2 hours) 3
Individuals with Documented Deficiencies
- Vitamin B12 supplementation (1,000 mcg daily orally) is appropriate only when deficiency is documented, with monitoring at 3,6, and 12 months 3
- Iron supplementation (45-60 mg elemental iron daily) should only be used for documented iron deficiency, taken with vitamin C for improved absorption and separated from calcium by 1-2 hours 3
Critical Safety Considerations
Medication Interactions
- Grapefruit can significantly interact with statins and many common medications, increasing blood levels when taken concurrently 1
- Antioxidant vitamins adversely interact with niacin, reducing its antiatherosclerotic benefits 1
- Mineral oil interferes with fat-soluble vitamin absorption (vitamins A, D, E, K) 4
- Thiazide diuretics combined with vitamin D can cause hypercalcemia in susceptible individuals 4
Common Pitfalls to Avoid
- Most patients do not disclose supplement use to healthcare providers, creating risk for unrecognized drug-supplement interactions 5, 6
- Over-the-counter supplements may be adulterated with banned or dangerous substances, particularly weight loss products 7
- Vitamin D has a narrow therapeutic window between beneficial and toxic doses, requiring individualized dosing and monitoring 4
- Vitamin A and E supplementation may cause toxicity, particularly in patients with kidney disease 1
When Supplementation May Be Harmful
- Chromium supplementation lacks conclusive evidence for glycemic control benefits in diabetes, despite some positive reports 1
- Omega-3 fatty acid supplements are not routinely recommended for cardiovascular disease prevention in healthy adults, though they may reduce triglycerides in specific populations 1
- Weight loss supplements are ineffective for obesity management and carry significant safety risks 1, 7
Essential Clinical Actions
- Always obtain a complete supplement history when collecting medication information, as patients often do not consider supplements to be medications 6, 8
- Evaluate total vitamin D intake from all sources (fortified foods, dietary supplements, prescription drugs) before prescribing, as therapeutic doses must be individualized 4
- Monitor for signs of toxicity when patients are taking fat-soluble vitamins (A, D, E, K), particularly in older adults or those with renal impairment 1, 4
- Counsel patients that supplement appearance does not indicate therapeutic properties, as products in medicinal forms do not necessarily have drug-like efficacy 7
Baseline Nutrition Assessment
- Dietary adequacy should be evaluated first before considering supplementation, as improvements in diet quality are essential and superior to supplementation for meeting nutritional needs 2
- Multivitamin supplementation in well-nourished individuals lacks consistent evidence for chronic disease prevention, though some data suggest modest cancer and cataract reduction in men 2
- Baseline nutritional status modifies supplement effects, making supplementation more beneficial in those with true deficiencies versus those who are already well-nourished 2