The body produces vitamin D from cholesterol in your skin upon exposure to sunlight. However, those who live far from the equator may be deficient in this vitamin.
The symptoms of vitamin D deficiency are subtle and may develop over years or even decades. These symptoms include bone loss, muscle weakness, and an increased risk of fractures.
Children with vitamin D deficiency may experience growth problems and soft bones (rickets). Vitamin D deficiency is also linked to reduced immune function and an increased risk of cancer.
Only a handful of foods contain significant amounts of vitamin D.
If you are deficient in vitamin D, take a supplement or increase your sun exposure. It may be difficult to get sufficient amounts of the vitamin through diet alone.
Unlike other vitamins, vitamin D is produced by the body. Dr. Todd Sontag, a family medicine specialist at Orlando Health in Florida, explains that the vitamin functions more like a hormone than an actual vitamin, since the human body has many vitamin D receptors. The majority of the immune system has vitamin D receptors.
Sufficient vitamin D levels help promote bone health and prevent the following health conditions:
In a study published in the International Journal of Nanomedicine, researchers from Ohio University used high-tech nanosensors to examine the relationship between vitamin D levels and heart health.
They specifically observed endothelial cells, which are cells that line the blood vessels and help control blood circulation and cardiovascular health.
Many health problems, including diabetes and hypertension, can damage endothelial cells. Damaged endothelial cells are linked to a higher risk of heart attack.
According to the study, vitamin D3 -- a form of vitamin D produced by the skin -- helps restore the health and strength of endothelial cells.
In a 2014 study published in the journal Neurology, scientists examined the connection between vitamin D deficiency and risk factors for different types of dementia, such as Alzheimer’s disease.
The researchers observed over 1,600 older adults who didn't have dementia at the start of the study.
They reported that volunteers with moderately low vitamin D levels had a higher chance of developing dementia than those with normal vitamin D levels. Meanwhile, volunteers with severe vitamin D deficiency had an even higher dementia risk.
The researchers concluded that vitamin D deficiency is linked to a substantially increased risk of dementia and Alzheimer's. (Related: Are you deficient in vitamin D? Here’s why it’s a big deal.)
Exposure to sunlight is one of the best ways to obtain vitamin D.
Unfortunately, most individuals feel depressed during the low-light winter months. This is one reason why experts believe there is a link between vitamin D and depression.
A 2008 study suggests that taking vitamin D supplements can reduce the symptoms of depression in overweight and obese people. Meanwhile, a 2013 study found that individuals with low concentrations of vitamin D are more likely to develop depression.
In a 2018 study, scientists from the University of Birmingham discovered that higher levels of vitamin D help boost muscle strength.
For the study, researchers measured the active and inactive vitamin D levels of participants, along with overall physical characteristics like body fat and muscle bulk. They revealed that increased levels of active vitamin D can promote and optimize muscle strength.
In a 2018 study published in the journal PLOS One, scientists reported that individuals with vitamin D deficiency may have a higher risk of developing Type 2 diabetes. For the study, they examined healthy, older adults with no prior warning signs of diabetes or prediabetes.
After 12 years, the majority of the volunteers developed diabetes or prediabetes. The researchers noted that vitamin D deficiency was a strong predictor of whether the volunteers would develop these conditions.
To improve your bone health and lower your risk of developing conditions like diabetes, consume vitamin D-rich foods and get enough sun exposure before 10 in the morning.