Vitamin D

Vitamin D is an important nutrient. It helps your body build strong bones and teeth. Maintaining an adequate level of vitamin D is important for all stages of life. It is especially important for children while their bones and teeth are developing. Vitamin D has other health benefits, as well. Vitamin D may protect against various health conditions, such as some cancers, muscle weakness, mood disorders, diabetes, kidney disease, heart disease, and high blood pressure.

Path to improved health

You can get Vitamin D from certain foods, sunlight, and dietary supplements.

Vitamin D is sometimes called the “sunshine vitamin.” That’s because your body creates its own vitamin D when you are exposed to sunlight. Depending on where you live, you might only need 10 minutes of sunshine 3 to 4 times a week to help your body create the vitamin D it needs. This can happen while you’re taking your dog for a walk or your children to the park. During certain times of the year, especially in northern states, there may not be enough of the right sunlight to make vitamin D. This is true even if you are outside all day.

Most people get very little vitamin D from the foods they eat. That’s because there are very few foods that contain vitamin D. Foods that naturally contain vitamin D include fatty fish, fish oil, eggs, cheese, and butter. There are also foods and drinks that have been fortified with vitamin D. These include milk, milk alternatives, some brands of orange juice, and some vitamin-fortified breakfast cereals. Read the food nutrition labels to learn if the products you choose are sources of vitamin D.

Vitamin D is available over the counter and by prescription. If you are concerned that you are not getting enough vitamin D, talk to your doctor. They will ask you about your diet and your exposure to sunlight. Your doctor also will consider other risk factors you may have.

Your doctor may want to test your level of vitamin D. This can be done through a blood test (inserting a small needle into your vein and taking a sample of blood to send to a lab). This will help determine if you need a supplement and, if so, how much. If you are a senior, a vegetarian or vegan, a nursing mother, or a pregnant woman, talk to your doctor about whether you should take a vitamin D supplement.

Things to consider

A low level of vitamin D in the body is called a vitamin D deficiency. Children who don’t get enough vitamin D are at risk for rickets. Rickets is a disorder that affects the bones. It causes bones to soften and break easily. Vitamin D deficiency can delay a child’s growth. And it can lead to cavities and problems with teeth structure. Adults who do not get enough vitamin D are at risk for osteomalacia (weak bones), osteoporosis (thin bones), and muscle weakness. This can increase the risk of bone fractures and falls.

The amount of vitamin D your body needs can vary depending on several factors, including:

• Weight
• Genetics
• Skin color
• Chronic conditions
• Where you live
• Sun exposure

Adults 70 years old and younger need 600 international units (IU) of vitamin D a day. Adults over the age of 70 need 800 IUs of vitamin D a day. For children between the ages of 1 and 18, the recommended daily dose is 600 IU. For children from birth to 12 months of age, the recommended daily dose is 400 IU.

If you breastfeed your baby, your doctor may prescribe a vitamin D supplement. Breast milk only has a small amount of vitamin D. Talk to your family doctor before giving older children vitamin supplements.

Vitamin D deficiency risk factors:

Some people are at higher risk for vitamin D deficiency than others, including:

• Infants who are only breastfed
• Babies and toddlers who are given non-milk food products or foods that are not fortified with vitamin D
• Seniors or older adults
• Darker-skinned people
• Those with limited exposure to sunlight (this includes people who are homebound)
• People who have difficulty absorbing dietary fat (because of conditions such as colitis, inflammatory bowel disease, and cystic fibrosis)
• Vegans, ovo-vegetarians, and those with other dietary restrictions such as milk-allergies and lactose-intolerance
• People who have a body mass index (BMI) greater than 30
• People with kidney disease, including kidney transplant recipients
• Those on medicines called glucocorticoids

People who live in northern states can also be at high risk. This is especially true during winter months. The farther south you live, the easier it is to get your vitamin D from sun exposure all year round.

Questions to ask your doctor

• Can a vitamin D deficiency make you feel overly tired?
• Can too much vitamin D be bad for your health?
• Are there any side effects to vitamin D dietary supplements?
• Can you get adequate sunlight by sitting near a window?

Resources

National Cancer Institute: Vitamin D and Cancer Prevention

National Institutes of Health, Office of Dietary Supplements: Vitamin D