A standard multivitamin contains all 13 essential vitamins and a range of minerals, typically between 10 and 15. The 13 vitamins are A, C, D, E, K, and the eight B vitamins (B1, B2, B3, B5, B6, B7, B9, and B12). Beyond that core set, most formulas include minerals like calcium, iron, zinc, magnesium, selenium, iodine, and several trace minerals. The exact amounts and which extras are included vary by brand and by who the product is designed for.
The 13 Essential Vitamins
Every multivitamin is built around the same 13 vitamins your body needs but can’t produce enough of on its own. They fall into two groups based on how your body absorbs and stores them.
Fat-soluble vitamins (A, D, E, K) dissolve in fat and get stored in your liver, fatty tissue, and muscles. Because they accumulate over time, taking large amounts through supplements can cause them to build up and potentially cause harm. You absorb them best when you take your multivitamin with a meal that contains some fat.
Water-soluble vitamins (C and all eight B vitamins) don’t get stored in your body the same way. Any excess leaves through your urine, which means you need a steady intake to avoid running low. The one exception is B12, which your liver can store for years.
Here’s what each one does in practical terms:
- Vitamin A: Supports vision, immune function, and skin health. The FDA daily value is 900 mcg.
- Vitamin C: Helps repair tissue and supports immune defenses. Daily value is 90 mg.
- Vitamin D: Drives calcium absorption for bone strength. Daily value is 20 mcg (800 IU).
- Vitamin E: Acts as an antioxidant protecting cells from damage. Daily value is 15 mg.
- Vitamin K: Essential for blood clotting and bone metabolism. Daily value is 120 mcg.
- B1 (thiamin): Converts food into energy. Daily value is 1.2 mg.
- B2 (riboflavin): Supports energy production and cell function. Daily value is 1.3 mg.
- B3 (niacin): Helps with digestion, nerve function, and skin health. Daily value is 16 mg.
- B5 (pantothenic acid): Involved in making hormones and processing fats. Daily value is 5 mg.
- B6: Supports brain development and immune function. Daily value is 1.7 mg.
- B7 (biotin): Helps metabolize fats and carbohydrates. Daily value is 30 mcg.
- B9 (folate): Critical for cell division and DNA formation. Daily value is 400 mcg.
- B12: Keeps nerve cells healthy and helps make red blood cells. Daily value is 2.4 mcg.
Common Minerals in Multivitamins
Most multivitamins include a selection of major minerals and trace minerals. The major minerals, needed in larger quantities, typically include calcium (daily value 1,300 mg), magnesium (420 mg), phosphorus (1,250 mg), potassium (4,700 mg), and zinc (11 mg). In practice, calcium, magnesium, and potassium are physically bulky, so multivitamins rarely contain anywhere near 100% of those daily values. If you see a one-a-day tablet listing only 200 mg of calcium, that’s normal. Getting the full amount from a single pill would make it enormous.
Trace minerals are needed in much smaller quantities. These include iron (18 mg), iodine (150 mcg), selenium (55 mcg), copper (0.9 mg), manganese (2.3 mg), chromium (35 mcg), and molybdenum (45 mcg). Trace minerals are critical for immune function, hormone production, and enzyme activity despite the tiny doses involved. Molybdenum, for example, helps your body break down toxins and process sulfites that could otherwise damage your nervous system.
How Formulas Differ by Age and Gender
Not all multivitamins contain the same amounts. Formulas marketed to women tend to contain higher levels of iron, folate, and biotin. The reason is straightforward: women of reproductive age need about 18 mg of iron daily compared to 8 mg for men the same age, largely because of menstrual blood loss. Folate is especially important for women who may become pregnant, since it reduces the risk of neural tube defects in early fetal development.
Multivitamins designed for adults over 50 adjust in a different direction. They typically boost vitamin B12 because many people past that age have trouble absorbing B12 from food. Vitamin D also goes up. People aged 51 to 70 need at least 15 mcg (600 IU) daily, and those over 70 need at least 20 mcg (800 IU). Calcium recommendations increase for women over 50 as well, rising from 1,000 mg to 1,200 mg to protect against bone loss. Men’s formulas for seniors often reduce or eliminate iron entirely, since men and postmenopausal women rarely need supplemental iron.
Prenatal multivitamins are their own category. They prioritize higher doses of folate, iron, and iodine. Women who have previously had a pregnancy affected by a neural tube defect may be advised to take up to 4,000 mcg of folic acid, ten times the standard daily value.
What’s Not on the Label (or Not Enough)
A common misunderstanding is that a multivitamin covers 100% of everything you need. Several important nutrients are either absent or present in token amounts. Calcium and magnesium are the biggest gaps. The daily value for calcium is 1,300 mg and for magnesium is 420 mg, but a typical tablet provides only a fraction of that. Potassium, with a daily value of 4,700 mg, appears in even smaller amounts. Choline (daily value 550 mg) is left out of many formulas entirely.
Some multivitamins also include extras that aren’t classified as essential vitamins or minerals, like lutein for eye health or lycopene as an antioxidant. These additions vary widely by brand and aren’t standardized.
Why the Form of Each Vitamin Matters
The same vitamin can appear on a label in different chemical forms, and this sometimes affects how well your body uses it. For vitamin C, though, the difference is less dramatic than marketing suggests. Natural and synthetic vitamin C are chemically identical, with no known difference in biological activity. Adding plant compounds called bioflavonoids doesn’t meaningfully change absorption either, based on results from 10 clinical studies comparing the two. One form that may actually absorb worse is timed-release vitamin C: one study found absorption was 50% lower from a slow-release capsule compared to a standard tablet.
For other nutrients, form matters more. Folate may appear as folic acid (synthetic) or methylfolate (the active form your body uses directly). B12 comes as cyanocobalamin, which is cheap and stable, or methylcobalamin, the form already active in the body. If a label calls out these specific forms, it’s generally a sign the manufacturer is paying attention to absorbability.
How to Tell if a Multivitamin Is Reliable
Dietary supplements in the United States aren’t tested by the FDA before they go on shelves, so third-party testing marks are the best quality signal available. NSF International certifies supplements against the only American National Standard for dietary supplements, which involves three checks: confirming the actual contents match the label, reviewing the formulation for safety, and screening for contaminants or undeclared ingredients. NSF conducts annual audits and periodically retests products to make sure they stay compliant.
For athletes, the NSF Certified for Sport program goes further, screening for over 280 substances banned by major athletic organizations, including stimulants, steroids, and masking agents. USP (United States Pharmacopeia) verification is another respected mark that tests for purity, potency, and whether the tablet will dissolve properly. If a multivitamin carries either of these seals, you can be reasonably confident that what’s listed on the label is actually inside the pill.