Draft Research Plan
Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer
May 23, 2019
Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.
- What is the efficacy of multivitamin supplementation on health outcomes in the general adult population?
- What are the harms of multivitamin supplementation in the general adult population?
- What is the efficacy of supplementation with single nutrients or functionally related nutrient pairs on health outcomes in the general adult population?
- What are the harms of supplementation with single nutrients in the general adult population?
The contextual question will not be systematically reviewed and is not shown in the Analytic Framework.
- What is the effect of vitamin and mineral supplementation on cardiovascular disease risk factors (e.g., high blood pressure, abnormal lipid levels, or type 2 diabetes mellitus) and precancerous outcomes (e.g., adenomas or cervical dysplasia)?
The Proposed Research Approach identifies the study characteristics and criteria that the Evidence-based Practice Center will use to search for publications and to determine whether identified studies should be included or excluded from the Evidence Report. Criteria are overarching as well as specific to each of the key questions (KQs).
|Populations||KQs 1, 3: Community-dwelling adults (age ≥18 years), including those:
KQs 2, 4: Community-dwelling adults without chronic disease
|Populations that only include pregnant women, infants, persons with chronic diseases (e.g., cancer, cardiovascular disease, type 2 diabetes mellitus, HIV, end-stage renal disease, tuberculosis, arthritis, or chronic pain), persons with clinical nutritional deficiencies, persons taking prescribed medications that may influence nutritional absorption or status, or institutionalized or hospitalized persons
Studies will be excluded if ≥50% of patients have known nutritional deficiencies, cardiovascular disease, type 2 diabetes mellitus, personal history of cancer (other than nonmelanoma skin cancer) or are taking prescription medications that may influence nutritional absorption or status
|Setting||Trials conducted in countries rated as “very high” on the 2017 Human Development Index (as defined by the United Nations Development Programme)||Trials conducted in countries rated as “very high” on the 2017 Human Development Index (as defined by the United Nations Development Programme)|
|Interventions||KQs 1, 2: Supplementation with multivitamins/minerals, defined as three or more vitamins, minerals, or combinations of both without added herbs, hormones, or drugs, each at a dose less than the tolerable upper intake level, as determined by the Food and Nutrition Board
KQs 3, 4: Supplementation with single nutrients and functionally related pairs (i.e., calcium; folic acid; vitamins B1, B2, B6, B12, D, E, C, and A; iron; zinc; magnesium; niacin; calcium/vitamin D; calcium/magnesium; folic acid/vitamin B12; selenium; beta-carotene; and folic acid/vitamin D6), each at a dose less than the tolerable upper intake level, as determined by the Food and Nutrition Board
|Supplementation with other types of dietary supplements (e.g., herbal supplements, omega-3 fatty acids, amino acids, enzymes, proprietary products, fiber, garlic, or turmeric)|
|Comparisons||Placebo or no intervention||Supplementation with other vitamins or minerals|
|Outcomes||KQs 1, 3:
KQs 2, 4:
|KQs 1, 3: Intermediate measures of cardiovascular disease risk factors (i.e., systolic and diastolic blood pressure, lipid measures, and glucose measures)|
|Timing||All-cause mortality: Minimum of 1 year of followup
All other outcomes: No minimum followup
|Less than 1 year of followup (all-cause mortality only)|
|Study Designs||KQs 1, 3: Randomized controlled trials
KQs 2, 4: Randomized, controlled trials or, for serious harms only, comparative observational studies (cohort or case-control) or postmarket surveillance dataOnly randomized, controlled trials will be considered for studies showing paradoxical harmful effects on main outcomes (cancer incidence and cardiovascular disease incidence or events)
|All other study designs|