woman drinking vitamin d milk


Don't be D-ficient

  • Vitamin D is important for strong, healthy bones. It also helps your body fight off germs, and your nerves carry messages to and from your brain.
  • Some people are at higher risk for vitamin D deficiency, which is measured with a simple blood test.
  • You can take too much vitamin D. If you eat foods rich in vitamin D, don't go overboard with supplements.

Nearly every cell in your body uses vitamin D in some way. If you don't get enough vitamin D, you may feel fatigue, muscle pain, weakness, a deep achiness and have difficulty walking. But the signs of vitamin D deficiency are not always obvious.

What is vitamin D deficiency?

It’s common to be vitamin D deficient. Because sunshine naturally produces this vitamin, this deficiency is especially common for those of us who live in northern climates like Minnesota.

Vitamin D is important for strong, healthy bones. It also helps your body fight off germs, and for your nerves to carry messages to and from your brain. In children, vitamin D prevents rickets or soft bones. In older people, low vitamin D levels can lead to bone loss that increases the risk for fractures and soft bones that cause bone pain and muscle weakness.

A simple blood test can find out if you have a low vitamin D level. It is important to ask your doctor if testing for vitamin D may be helpful for you. It is also important to check to see if your insurance covers this testing.

Symptoms of a low vitamin D level

Signs and symptoms may differ in children and adults. Some common symptoms include:

  • achiness
  • childhood growth problems
  • difficulty walking
  • fatigue and general weakness
  • mood changes
  • muscle pain and cramping.

Sources of vitamin D

You can get vitamin D in three ways:

  1. Food and drinks. Only a handful of foods naturally contain vitamin D. The best sources of vitamin D are:
    • fatty fish such as salmon or tuna.
    • mushrooms
    • nearly all milk has vitamin D added. This includes many plant-based products such as almond, oat and soy milk. Read the food labels to find out how much vitamin D has been added.
  2. Sun exposure. Vitamin D is known as the “sunshine vitamin” because your body makes vitamin D when your skin is exposed to direct sunlight. Cloud cover, shade and using sunscreen or clothing to protect your skin from the sun will cut down the amount of vitamin D your skin makes. Age and skin color can affect the amount of vitamin D you absorb.
  3. Supplements. The easiest way to get vitamin D is through supplements (vitamins).

Causes of vitamin D deficiency

Some people are at higher risk for vitamin D deficiency. For example, your skin’s ability to absorb vitamin D decreases as you age. You are most at risk for being vitamin D deficient if you:

  • have a disease that causes problems with your body absorbing nutrients from food. Some examples include Crohn’s and celiac disease, and cystic fibrosis.
  • have liver and kidney disease which reduces an enzyme important to vitamin D conversion in your body.
  • have had bariatric (weight loss) surgery which make it hard to absorb enough nutrients from food. You will probably need to take a supplement the rest of your life if you’ve had this type of surgery.
  • are obese. A body mass index (BMI) of 30 or more can mean vitamin D becomes trapped in fat cells. You may need a higher daily dose of vitamin D to maintain a normal level.
  • have dark skin which absorbs less vitamin D.
  • take some common medicines such as anti-seizure and cholesterol-lowering medicine and steroids.

Treatment of vitamin D deficiency

If you are deficient in vitamin D, supplements can help you get to the recommended level. In addition to taking a supplement, try spending up to 15 minutes outdoors in the sun when you can. Be sure to wear an SPF 30 or higher sunscreen if you plan to be in the sun for more than 15 minutes. This will lower your risk of developing skin cancer.

Keep in mind that sunlight filtered through a window will not help your body make vitamin D. And, in the northern half of the United States, including Minnesota and Wisconsin, energy from the sun is not enough for skin to make vitamin D between late fall and early spring.

If you are at risk for low vitamin D levels or are having symptoms, talk with your health care provider or schedule a virtual visit.

How much vitamin D do you need?

Adults need the following amounts of vitamin D each day:

  • ages 18 to 70: 600 (international units) UI
  • ages 71 and older: 800 IU
  • women who are pregnant or breastfeeding: 600 IU.

The safe upper limits of vitamin D a day for adults and pregnant or breastfeeding women is 4,000 IU a day. Breastfed infants generally need a vitamin D supplement. Discuss this with your child's pediatrician.

You can take too much vitamin D. Because it’s fat soluble, vitamin D is stored in fat cells and too much can be toxic. So, if you eat plenty of food naturally containing vitamin D or fortified with it, don't go overboard with supplements.

Concerned about your vitamin D level? Talk with your health care provider or schedule a virtual visit.


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