Vitamin D is known as the “sunshine” vitamin. It is an essential fat-soluble nutrient. It helps keep bones healthy and strong, helps cell growth, and benefits immune function.

Your body absorbs vitamin D primarily through sun exposure, although dietary supplements and certain foods are also sources of the nutrient.

Vitamin D deficiency occurs when your body doesn’t absorb the recommend levels. Insufficient vitamin D levels can cause your bones to become misshapen, brittle, or thin. It can also lead to a number of health problems, including:

  • bone softening (osteomalacia)
  • low bone density (osteopenia)
  • osteoarthritis
  • heart disease
  • cancer
  • rickets in children

 

Vitamin D and depression

Studies have shown a link between vitamin D deficiency and depression. Researchers behind a 2013 meta-analysis noticed that study participants with depression also had low vitamin D levels. The same analysis found that, statistically, people with low vitamin D were at a much greater risk of depression.

The researchers believe that because vitamin D is important to brain function, insufficient nutrient levels may play a role in depression and other mental illnesses. An earlier 2005 study identified vitamin D receptors in the same areas of the brain associated with depression.

Risk factors for vitamin D deficiency

Limited sun exposure, lifestyle, and age can contribute to low vitamin D levels. Keep reading to learn more about the risk factors for vitamin D deficiency.

Sun exposure

Sunlight exposure is the primary source of vitamin D for most people. If you stay out of the sun or use too much sunblock you limit your exposure. That can lead to vitamin D deficiency.

The amount of sun exposure you need will depend on your climate, the time of day, and the time of year. People with lighter skin tend to absorb vitamin D more quickly. You may need anywhere from 15 minutes to 2 hours of exposure per day to get enough vitamin D from sun exposure alone.

Diet

Few foods are naturally rich in vitamin D. Eat more of these great natural sources of vitamin D to increase your intake:

  • salmon
  • mackerel
  • other fatty fish
  • fish liver oils
  • animal fats
  • vitamin D fortified food products, like orange juice and cereal

 

If you adhere to a vegan or vegetarian diet, there’s a chance you’re not getting enough vitamin D.

Darker skin tone

People who have darker skin have greater amounts of melanin. Melanin reduces vitamin D production in the skin.

A 2006 study found that in the United States, vitamin D deficiency is more prevalent among African-Americans than other American populations. It’s unclear if lower vitamin D levels in people with darker skin have serious health implications.

If you are concerned about your vitamin D production from sun exposure, talk with your doctor about what you can do and try adding more foods rich in vitamin D to your diet.

Higher latitudes

Studies published in The Journal of Nutrition and the International Journal of Circumpolar Health both found that people living in northern latitudes, such as the northern half of the United States might have lower vitamin D levels.

If the area where you live gets less sun, you may need to spend more time outside to increase your sun exposure.

Obesity

A link exists between vitamin D deficiency and people with a body mass index (BMI) of 30 or higher. People who are obese may need to absorb more vitamin D than people of average weight in order to reach recommended nutrient levels.

If your BMI is 30 or higher, work with your doctor to come up with a manageable weight loss plan.

Age

Age can contribute to vitamin D deficiency. As you get older, your skin becomes less efficient at synthesizing vitamin D. Older adults also tend to limit time in the sun and may eat diets with insufficient amounts of vitamin D.