The Importance of Vitamin D


What is vitamin D?

Commonly referred to as “the sunshine vitamin,” the primary source of obtaining vitamin D is exposure to the sun. Vitamin D regulates the absorption of calcium and phosphorus in the body; therefore, it is an essential vitamin for bone health. It also has anti-inflammatory, antioxidant, and neuroprotective properties. Healthy levels of vitamin D are necessary to achieve and maintain optimal health.

Benefits of maintaining healthy vitamin D levels

Not only is vitamin D necessary to build and maintain strong bones, it also strengthens the immune system, supports muscle function, helps regulate brain function, and promotes a healthy nervous system.

Maintaining healthy levels of vitamin D provides many health benefits and reduces the risk and/or severity of various medical conditions. Benefits of maintaining healthy vitamin D levels include the following:

Sources of vitamin D

The main source of vitamin D is exposure to the sun. Because too much sun exposure can cause sunburn and skin cancer, individuals often use sunscreen or cover up to avoid ultraviolet rays. Unfortunately, while these protective measures are effective in keeping one safe from the dangers of the sun, they can inadvertently cause a vitamin D deficiency.

A few foods, such as fatty fish (e.g., salmon, mackerel, sardines, etc.) and eggs, naturally contain vitamin D; however, some foods are fortified with vitamin D, such as milk, certain cereals, and orange juice. However, the amount of vitamin D in these food sources is inadequate for the body's needs. In order to obtain the proper levels of vitamin D, approximately 15–30 minutes of sun exposure each day or a vitamin D supplement is typically needed.

Healthy levels

The recommended daily allowance of vitamin D is 400 international units (IU) for children up to 12 months of age, 600 IU for ages 1 to 70 years, and 800 IU for those over 70 years. Women who are pregnant or breastfeeding are recommended to absorb 600 IU (15 mcg) daily.

Vitamin D deficiency

Vitamin D deficiency is one of the most common nutritional deficiencies globally. For example, approximately 42% of adults in the United States are vitamin D deficient; this number increases in the African American population (82% of adults) and the Hispanic population (63% of adults). A health care professional can order a simple blood test to determine if an individual is vitamin D deficient.

While a mild vitamin D deficiency may not cause any symptoms, a moderate or severe vitamin D deficiency may cause bone pain and muscle weakness. Other symptoms may include, but are not limited to, the following:

  • Fatigue
  • Aching muscles
  • Binge eating
  • Weight gain
  • Low mood
  • Reduced cognitive function (memory, clarity)
  • Sleep issues
  • Hair loss
  • Dizziness
  • Recurring infections
  • Low back pain
  • Slow wound healing

Taking too much vitamin D in supplement form

Taking too much vitamin D can also be harmful. No more than 4000 IU should be consumed daily in supplement form unless ordered by a qualified health care professional. Consult a health care provider to determine the best dosage for individual needs.

Taking over 4,000 IU of vitamin D a day can cause the following:

  • Nausea
  • Vomiting
  • Constipation
  • Falls and fractures
  • Poor appetite, resulting in weight loss
  • Confusion/disorientation
  • Weakness
  • Kidney stones or damage
  • Abnormal heart rhythm