Vitamin D: sunlight, food, and what the sources say about supplements

What vitamin D does

MedlinePlus (US) says vitamin D helps your body absorb calcium. ODPHP (US) says the same, and explains that absorbing means taking in. MedlinePlus adds that vitamin D comes from three places: sunlight on your skin, food, and supplements. [1] [2]

Sunlight

MedlinePlus (US) says your body forms vitamin D naturally after sunlight reaches your skin. ODPHP (US) agrees that your body makes vitamin D when you are out in the sun. [1] [2]

Sun also has a downside. MedlinePlus (US) warns that too much sun can lead to skin aging and skin cancer. It also says the skin limits how much vitamin D it makes, so sun alone cannot give you too much vitamin D. [1]

Food

MedlinePlus (US) says only a few foods naturally have some vitamin D. ODPHP (US) names fish such as salmon, tuna, and trout. It also lists foods that have vitamin D added, including milk or soy milk. Some breakfast cereals, yogurts, and juices are on its list too. [1] [2]

Supplements and who may be at risk

ODPHP (US) lists vitamin D pills as one more way to get vitamin D. The Office on Women's Health (US) takes a careful view of supplements in general. It says most women do not need a vitamin or mineral supplement. It adds that many supplements are safe, especially those a doctor or nurse recommends. [2] [3]

MedlinePlus (US) says some people are at higher risk of not having enough vitamin D, a condition called vitamin D deficiency. Its list includes older adults, because aging skin makes vitamin D from sunlight less well. It also names people with dark skin and people who have obesity. When someone has a deficiency, it says, the treatment is supplements. [1]