How much vitamin D per day, by age, pregnancy and 50+

Most adults need 15 mcg (600 IU) of vitamin D per day, rising to 20 mcg (800 IU) at age 71 and older, according to the NIH Office of Dietary Supplements. The Tolerable Upper Intake Level from all sources combined is 100 mcg (4,000 IU) per day for everyone aged 9 and older, including during pregnancy and lactation.

What vitamin D does in the body

Vitamin D has several well-established physiological roles. It promotes calcium absorption in the gut and helps maintain adequate serum calcium and phosphate concentrations, which are needed for normal bone mineralization. It also helps prevent hypocalcemic tetany, a condition involving involuntary muscle contractions, cramps, and spasms that can occur when blood calcium falls too low. Alongside calcium, vitamin D supports bone growth and remodeling carried out by osteoblasts and osteoclasts, and helps protect older adults from osteoporosis.

Vitamin D deficiency causes rickets in children and osteomalacia in adults. The evidence for these roles is graded strong by the NIH.

Recommended daily amounts by age

The figures below come from the NIH Office of Dietary Supplements Dietary Reference Intakes. They cover total intake from food, beverages, and supplements combined.

• Birth to 12 months: 10 mcg (400 IU) per day
• Ages 1 to 70: 15 mcg (600 IU) per day
• Ages 71 and older: 20 mcg (800 IU) per day
• Pregnancy and lactation (all ages): 15 mcg (600 IU) per day

The Tolerable Upper Intake Level (UL) is the highest daily amount considered unlikely to cause harm for most healthy people. Staying within the UL avoids the risk of hypercalcemia, a condition of abnormally high blood calcium.

• Birth to 6 months: 25 mcg (1,000 IU)
• Ages 7 to 12 months: 38 mcg (1,500 IU)
• Ages 1 to 3: 63 mcg (2,500 IU)
• Ages 4 to 8: 75 mcg (3,000 IU)
• Ages 9 and older, including pregnancy and lactation: 100 mcg (4,000 IU)

A healthcare provider may prescribe higher doses for specific clinical reasons, such as correcting a confirmed deficiency. Do not exceed the UL without medical supervision.

Vitamin D for people over 50

Bone density naturally declines with age, and vitamin D together with calcium plays a supporting role in bone health throughout later life. According to the NIH, vitamin D plus calcium supplements can slightly increase bone mineral density in some postmenopausal women and older men, and may reduce fracture rates in institutionalized older people. The NIH grades this evidence as moderate. Evidence that vitamin D supplements reduce falls or fractures in community-dwelling older adults is graded limited, meaning the findings are promising but not yet consistent enough to draw firm conclusions.

People aged 71 and older have a higher recommended intake of 20 mcg (800 IU) per day. If you are in this age group and unsure whether you are meeting this target through diet alone, speak with your clinician before adding a supplement.

Vitamin D during pregnancy and lactation

The recommended intake during pregnancy and lactation is 15 mcg (600 IU) per day, the same as for other adults under 71. The Tolerable Upper Intake Level remains 100 mcg (4,000 IU) per day. Because vitamin D status can affect both the pregnant person and the developing baby, individual needs vary. Your midwife, obstetrician, or general practitioner is the right person to advise on whether supplementation is appropriate for your situation.

What the evidence does and does not support

It is important to understand what research currently shows and where evidence is still limited.

• Strong evidence: Vitamin D promotes intestinal calcium absorption and maintains serum calcium and phosphate for normal bone mineralization.
• Strong evidence: Vitamin D deficiency causes rickets in children and osteomalacia in adults.
• Moderate evidence: Vitamin D plus calcium supplements slightly increase bone mineral density in some postmenopausal women and older men and can reduce fracture rates in institutionalized older people.
• Limited evidence: Vitamin D supplements reduce falls or fractures in community-dwelling older adults.
• Insufficient evidence: Vitamin D supplements prevent or treat cancer, cardiovascular disease, depression, multiple sclerosis, type 2 diabetes, or aid weight loss. The NIH does not support these claims based on current research.

Vitamin D supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA.

Drug interactions to know about

Vitamin D can interact with several common medications. Talk to your doctor or pharmacist before combining vitamin D supplements with any prescription or over-the-counter drug, particularly the following.

• Orlistat (Xenical, alli): This weight-loss drug can reduce absorption of vitamin D from food and supplements.
• Statins (for example atorvastatin/Lipitor, lovastatin/Altoprev, simvastatin/FloLipid, Zocor): These cholesterol-lowering drugs may not work as well when taken alongside high-dose vitamin D supplements.
• Corticosteroids such as prednisone (Deltasone, Rayos, Sterapred): Long-term use can lower blood levels of vitamin D.
• Thiazide diuretics (for example chlorthalidone/Hygroton, indapamide/Lozol, hydrochlorothiazide/Microzide): When combined with vitamin D supplements, these blood pressure medications can raise blood calcium to an unsafe level.

Getting vitamin D from food and sunlight

Dietary sources of vitamin D include fatty fish such as salmon and tuna, fish liver oils, egg yolks, and fortified foods such as milk, plant-based milk alternatives, and some breakfast cereals. The skin also makes vitamin D when exposed to ultraviolet B sunlight, though the amount produced depends on skin tone, latitude, season, sunscreen use, and age. Many people in northern latitudes or with limited sun exposure do not produce enough through sunlight alone.

When to speak to a clinician

The reference values on this page are population-level targets. Your personal requirement depends on your diet, sun exposure, health conditions, medications, and blood vitamin D levels. If you are considering a supplement or want to know whether your intake is adequate, consult a clinician or pharmacist for advice tailored to you. Never adjust a prescribed dose without guidance from your healthcare provider.

Sources: NIH Office of Dietary Supplements Vitamin D Fact Sheet for Health Professionals (https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/), NIH Office of Dietary Supplements Vitamin D Fact Sheet for Consumers (https://ods.od.nih.gov/factsheets/VitaminD-Consumer/), Dietary Reference Intakes for Calcium and Vitamin D (https://www.ncbi.nlm.nih.gov/books/NBK56070/).