Vitamins are substances that your body needs to grow and develop normally. Vitamin D 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. Vitamin D also has a role in your nerve, muscle, and immune systems.
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.
Vitamin D-rich foods include egg yolks, saltwater fish, and liver. Some other foods, like milk and cereal, often have added vitamin D.
You can also take vitamin D supplements. Check with your health care provider to see how much you should take. People who might need extra vitamin D include:
- Older adults
- Breastfed infants
- People with dark skin
- People with certain conditions, such as liver diseases, cystic fibrosis and Crohn's disease
- People who have obesity or have had gastric bypass surgery
NIH: National Institutes of Health Office of Dietary Supplements
Statistics and Research
- Vitamin D and Cancer Prevention (National Cancer Institute) Also in Spanish
- Vitamin D and Multiple Sclerosis (MS): Is There Any Connection? (Mayo Foundation for Medical Education and Research) Also in Spanish
- Vitamin D Supplements Don't Reduce Cancer Incidence, Trial Shows (National Cancer Institute)
- ClinicalTrials.gov: Vitamin D (National Institutes of Health)
Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
Find an Expert
- Find a Nutrition Expert (Academy of Nutrition and Dietetics)
- Food and Drug Administration
- Food and Nutrition Information Center
- National Institutes of Health, Office of Dietary Supplements
- Breastfeeding: Vitamin D Supplementation (Centers for Disease Control and Prevention)