If you already eat a reasonably balanced diet, a daily multivitamin can help cover any minor nutrient gaps. If you know you have or want to prevent specific deficiencies, this straightforward guide explains which supplements to take and when they are best absorbed.
See also Supplements: A Starter Course
MORNING
MULTIVITAMIN
A multivitamin fills dietary gaps and supplies nutrients that may be hard to get from food alone.
WHO IT’S FOR: People with unbalanced diets or those who avoid whole food groups such as meat, dairy or grains.
HOW TO TAKE IT: Take with a breakfast that includes healthy fats—avocado, eggs or olive oil—to improve absorption of fat-soluble vitamins.
NOTE: Many multivitamins also include folic acid, zinc and iron.
FORMULAS: Multis come tailored for different needs—women’s formulas often have more vitamin C and E and adjusted iron for older women; men’s options emphasize vitamins A, D and E; prenatal formulas contain higher folic acid; children’s products add vitamin D3 and omega-3s for immunity and brain development.
See also The Best Vitamins and Supplements for Kids
PROBIOTICS
Live bacterial strains that support healthy digestion and regularity.
WHO IT’S FOR: People who experience constipation, gas or frequent stomach discomfort.
HOW TO TAKE IT: Take on an empty stomach before breakfast for better survival of the beneficial bacteria.
FACT: Probiotic foods and supplements have become widely popular; fermented foods like yogurt are common sources.
B COMPLEX
A group of eight B vitamins that help convert food into usable energy and support nervous system function.
WHO IT’S FOR: Anyone who feels sluggish in the morning or wants steady energy without relying on caffeine.
HOW TO TAKE IT: Take first thing in the morning, with or before breakfast.
MORNING / AFTERNOON
COQ10
An antioxidant that helps protect cells and supports cardiovascular health.
WHO IT’S FOR: People with a family history of heart disease or those at risk for cardiovascular problems.
HOW TO TAKE IT: Take with a meal containing healthy fats for optimal absorption.
IODINE
An essential element for thyroid function and reproductive health.
WHO IT’S FOR: Pregnant women, people with thyroid disorders or anyone diagnosed with goiter. Iodine deficiency during pregnancy can cause serious complications for mother and child.
HOW TO TAKE IT: Take with food and no later than early afternoon—iodine can increase alertness and may interfere with sleep if taken too late.
ZINC
An essential trace element important for immune function, cell growth and prostate health.
WHO IT’S FOR: Vegetarians, people who avoid legumes, nuts or dairy, or those at risk for prostate issues.
HOW TO TAKE IT: Take with a meal—zinc can cause nausea when taken on an empty stomach.
AFTERNOON / EVENING
IRON
A mineral needed to produce red blood cells and carry oxygen throughout the body.
WHO IT’S FOR: Athletes who train intensely, pregnant or breastfeeding women, and those following vegetarian or vegan diets.
HOW TO TAKE IT: Start with a low dose and pair with extra dietary fiber or a stool softener if constipation is a concern.
FACT: Around 10% of women are iron deficient.
FIBER
Dietary fiber supports digestive regularity and overall gut health.
WHO IT’S FOR: People who eat few fruits and vegetables or who want better bowel regularity.
HOW TO TAKE IT: Take with at least 8 ounces of water, and space fiber supplements at least two hours away from medications and other supplements to avoid interactions.
FACT: Insoluble fiber acts like a broom, helping move waste through the digestive tract.
OMEGA-3 FATTY ACIDS
Essential fatty acids found in cold-water fish, nuts and seeds that support heart and brain health and may protect against inflammation-related conditions.
WHO IT’S FOR: People who do not eat enough seafood or who want cardiovascular and cognitive support.
HOW TO TAKE IT: Take with lunch or an afternoon snack to improve absorption; store fish oil in the refrigerator to preserve freshness.
EVENING / NIGHT
VITAMIN D & CALCIUM
Both nutrients are important for bone density, muscle function and overall skeletal health.
WHO IT’S FOR: People who get little sun exposure, adults over 50, and anyone who does not consume sufficient dairy or calcium-rich foods.
HOW TO TAKE IT: Take vitamin D and calcium together—vitamin D enhances calcium absorption. Evening dosing works well for many people, though timing can be adjusted if it interferes with sleep.
TIP: Even short daily sun exposure—about 10 minutes—can help maintain vitamin D levels.
See also The Best Supplements for Seniors
MAGNESIUM
A mineral important for bone and dental health, muscle relaxation and nervous system function.
WHO IT’S FOR: People with fatigue, anxiety, heartburn or constipation, or those who do not eat magnesium-rich foods such as dark leafy greens, nuts and beans.
HOW TO TAKE IT: Take magnesium alongside calcium in the evening; the combination supports bones and muscles and helps offset calcium-related constipation.
WATER-SOLUBLE VS. FAT-SOLUBLE VITAMINS
Fat-soluble vitamins (A, D, E and K) are absorbed with dietary fat and can be stored in body tissues until needed; too much accumulation can cause harm. Water-soluble vitamins (B-complex and C) are not stored and excess amounts are typically excreted in urine, so they require more regular replenishment.
RESOURCES & SOURCES
For official guidance and recommended intake levels, consult authoritative sources such as national health agencies and dietary reference intake tables. Credible organizations referenced for this overview include the National Institutes of Health Office of Dietary Supplements, the National Center for Complementary and Alternative Medicine, the Vitamin D Council, the National Osteoporosis Foundation, the Centers for Disease Control and the Institute of Medicine.