Vitamin D deficiency is widespread in the United States. Approximately 75 percent of adults and teens have low levels of vitamin D, according to the National Health and Nutrition Examination Survey. These deficiencies are related to numerous health conditions, including weak bones (osteoporosis), bone pain, heart disease, high blood pressure, diabetes, and several types of cancer.

Vitamin D is an important vitamin that affects several systems throughout the body. Unlike other vitamins, vitamin D actually functions like a hormone — your body makes it by itself, but only after your skin is exposed to sunlight. This can be a problem for people in northern climates — including most of the United States.

Who is at risk of vitamin D deficiency?

The only people in the US who get enough vitamin D from sunlight throughout the year live lower than 34 degrees north of the equator — that’s roughly a line drawn from Los Angeles to Columbia, South Carolina. In winter, it’s impossible to get vitamin D from the sun if you live anywhere north of Atlanta.

Darker skin absorbs less sunlight, so dark-skinned individuals often do not produce enough vitamin D from the sun alone. Only 3 percent of African Americans sampled were found to have the recommended levels of vitamin D. Hispanics were also found to be more at risk of vitamin D deficiency than people with lighter skin.

Individuals with certain genetic variants are also more likely to have lower levels of vitamin D. Individuals with a variant in the GC gene have a reduced ability to transport vitamin D within the body and should optimize their intake of vitamin D.

What symptoms are associated with vitamin D deficiency?

Symptoms of vitamin D deficiency are subtle and nonspecific — it’s difficult to tell if they are the result of vitamin D deficiency or something else. However, low vitamin D levels have been linked to problems such as:

  • Frequent colds or illness. Lack of vitamin D can suppress your immune system, causing you to get sick more often. Several studies have demonstrated a link between low vitamin D levels and respiratory illnesses such as bronchitis and pneumonia. Taking 4,000 IUs (international units) may help reduce the risk of respiratory tract infections.
  • Fatigue. Low blood levels of vitamin D can cause fatigue that has a severe impact on quality of life. However, vitamin D deficiency is often overlooked as a potential cause of the fatigue. Taking vitamin D supplements may help improve energy levels.
  • Bone pain and lower back pain. Vitamin D is necessary for the body to use and absorb calcium. So even if you’re getting enough calcium in your diet or from supplements, if your vitamin D levels are low, your bones may still be weak. Several studies have shown a link between low vitamin D levels and back pain.
  • Depression. Studies have a found a link between vitamin D deficiency and depression, particularly among older adults. Vitamin D supplements may help improve depression, including seasonal depression that occurs during the winter.
  • Slow wound healing. Impaired wound healing following surgery or injury may be an indication of low vitamin D levels. Vitamin D may increase compounds that help form new skin during the wound-healing process.

Can vitamin D be found in food?

It’s difficult to get enough vitamin D from diet alone, as few foods naturally contain it. Food sources include fish like salmon, mackerel, and tuna. Foods such as milk or orange juice are also often fortified with vitamin D.

If you live in a northern climate or otherwise don’t get enough sunlight, you may want to consider a vitamin D supplement. Calcium supplements often have vitamin D added, since the body can’t absorb calcium without vitamin D.

How much vitamin D should you get?

The recommended daily intake for vitamin D is about 600 IUs (international units). Some experts recommend getting much more than that.

The amount of sunlight you need to produce enough vitamin D depends on several factors, including where you live and how fair your skin is. During the summer, if you’re fair skinned, ten minutes of midday sun — without sunscreen — will provide you with roughly 10,000 IUs. Sunscreen blocks your ability to produce vitamin D — using a sunscreen with just SPF 15 decreases your vitamin D production by 99 percent.

To prevent skin cancer, it’s important to be smart about your sun exposure, and don’t let yourself get burned. Spend a few minutes outdoors without sunscreen to allow your body to produce vitamin D, but if you’re going to be outside longer, apply sunscreen.

Are you at risk of vitamin D deficiency?

Vivaliti DNA offers advanced genetic testing that can reveal certain genetic variants that affect your health — including variants of the vitamin D binding protein. Request a consultation with a Vivaliti DNA health coach today to learn how obtaining your individual genetic blueprint can help you make smarter choices about your health and wellness.