What are the recommendations for taking multivitamins (mv) for adults?

Multivitamin Recommendations for Adults

For most healthy adults, routine multivitamin supplementation is not necessary and should be reserved for specific at-risk populations including elderly individuals, pregnant or lactating women, strict vegetarians, and those on calorie-restricted diets. 1

General Population Guidance

The evidence does not support routine multivitamin use for preventing cardiovascular disease or cancer in community-dwelling, nonpregnant adults. 2 The U.S. Preventive Services Task Force concludes there is insufficient evidence to determine the balance of benefits and harms of multivitamin supplementation for these outcomes. 2

Key principle: Adults should prioritize obtaining daily vitamin and mineral requirements from natural food sources rather than supplements. 1

Specific Populations Who Should Consider Multivitamins

High-Risk Groups Requiring Supplementation

• Elderly individuals: A daily multivitamin supplement is appropriate, especially for those with reduced energy intake. 1
• Pregnant or lactating women: Multivitamin supplementation with iron and folic acid is advisable. 1
• Strict vegetarians: Should consider multivitamin supplementation due to potential nutrient gaps. 1
• Individuals on calorie-restricted diets: Supplementation helps prevent deficiencies when food intake is limited. 1

Patients with Chronic Kidney Disease

For adults with CKD stages 3-5D or post-transplantation, registered dietitian nutritionists should assess dietary vitamin intake periodically and consider multivitamin supplementation for those with inadequate intake. 1 For CKD 5D patients with sustained inadequate dietary intake, supplementation with multivitamins including all water-soluble vitamins and essential trace elements is reasonable to prevent micronutrient deficiencies. 1

Post-Bariatric Surgery Patients

Two adult multivitamin-mineral supplements daily (containing iron, folic acid, zinc, copper, selenium, and thiamin at 200% of the RDA) are required after most bariatric procedures, with only one supplement daily needed after laparoscopic adjustable gastric banding. 1

Safety Considerations

Dosing Limits

Multivitamin use within the range of Dietary Reference Intake is safe for long-term use (more than 10 years) and does not increase mortality. 3, 4 Only minor adverse effects such as nonspecific gastrointestinal symptoms have been reported, with no significant differences between treatment and placebo groups. 3, 4

Critical Warnings

Avoid beta carotene and vitamin E supplementation - these have demonstrated harms that outweigh benefits for cardiovascular disease and cancer prevention. 2

Folic acid precaution: Doses exceeding 0.4 mg daily should not be given until pernicious anemia is ruled out, as therapeutic doses may mask neurologic manifestations of vitamin B12 deficiency while correcting hematologic parameters. 5 Therapeutic amounts of folic acid should be given separately, not in multivitamin preparations. 5

Potential Toxicity Concerns

Patients must be educated about the potential toxicity of megadoses of vitamin and mineral supplements. 1 High dosages of antioxidants may lead to health problems including diarrhea, bleeding, and toxic reactions. 1 Vitamin and mineral supplementation in pharmacological dosages should be viewed as therapeutic intervention requiring placebo-controlled trials to demonstrate safety and efficacy. 1

Specific Nutrient Considerations

Vitamins to Avoid in Excess

• Vitamin A and E: Should not be routinely supplemented in CKD 5D patients due to potential toxicity. 1
• Vitamin E: No net benefit for cardiovascular disease or cancer prevention. 2

Recommended Dietary Allowances

For adults requiring supplementation, multivitamins should contain nutrients at levels close to RDAs rather than megadoses. 1 Products containing 12-13 vitamins at appropriate levels are preferred over incomplete formulations. 6

Clinical Practice Points

• Evaluation of micronutrient status begins with careful clinical history including food/nutrition history to document supplement use. 1
• Laboratory evaluation may be useful for serum folate, vitamin B12, vitamin D, calcium, potassium, magnesium, and iron concentrations. 1
• Up to 68% of physicians are unaware of supplement use among their patients, highlighting the need for explicit questioning. 1
• Approximately 52% of US adults use at least one dietary supplement, with 31% using multivitamin-mineral supplements. 2