Vitamin D

Source: MedlinePlus Health Topics, U.S. National Library of Medicine

Last synced 8/7/2026Status: primary verified

Why do I need vitamin D? Vitamins are substances that your body needs to grow and develop normally. Vitamin D is important to your body because: It helps your body absorb calcium . Calcium is one of the main building blocks of bone. A lack of vitamin D can lead to bone diseases such as osteoporosis or rickets . It also has a role in your nerve, muscle, and immune systems: Your muscles need it to move Your nerves need it to carry messages between your brain and your body Your immune system needs vitamin D to fight off bacteria and viruses How do I get vitamin D? You can get vitamin D in three ways: through your skin, from your diet, and from supplements. Your body forms vitamin D naturally after exposure to sunlight . However, too much sun exposure can lead to skin aging and skin cancer . So many people try to get their vitamin D from other sources. Very few foods naturally contain vitamin D. Most people get vitamin D in their diet from foods that are fortified. This means that vitamin D is added to the food. These foods may include milk, cereal, and yogurt. Foods that naturally have vitamin D include egg yolks, saltwater fish, and liver. Vitamin D is available in supplements. It is also included in many multivitamins. The two forms of vitamin D in supplements are D2 and D3. Both types increase vitamin D in your blood, but D3 might raise it higher and for longer than D2. Vitamin D is fat soluble. You can absorb it better when you take your supplements with a meal or snack that includes some fat. How much vitamin D do I need? The amount of vitamin D you need each day depends on your age. The recommended amounts, in international units (IU), are: Birth to 12 months: 400 IU Children 1-13 years: 600 IU Teens 14-18 years: 600 IU Adults 19-70 years: 600 IU Adults 71 years and older: 800 IU If you are pregnant or breastfeeding: 600 IU But certain people may need extra vitamin D, such as: Older adults Breastfed infants People with dark skin People with certain conditions tha

Educational only

This information is for general education and is not medical advice. Always talk to a licensed U.S. clinician about your situation, medications, or treatment decisions.