Vitamin D is the unsung hero that helps our bodies absorb calcium for strong bones and teeth, supports our immune system and even regulates cell growth and differentiation. Still, many of us don't consume enough through diet or sunlight exposure, leading to a deficiency with potentially serious consequences.
Did you know nearly 1 billion people worldwide have a vitamin D deficiency? According to the Cleveland Clinic, in the U.S., that equals around 35% of adults. These statistics are a serious concern because a vitamin D deficiency can wreak havoc on our health.
Vitamin D health benefits
Vitamin D receptors can be found in cells throughout the body, such as your bones, immune system, skin and more. When vitamin D connects with these receptors, it acts like a hormone by flipping switches inside your cells to control things like calcium levels, immune function and even cell growth. Vitamin D's most important role is supporting our bone health by helping our bodies absorb calcium from our diet, which is necessary for strong bones and teeth.
In addition to supporting our bones, vitamin D helps activate immune cells that can identify and attack harmful pathogens, such as viruses and bacteria, making it significant in regulating our immune function. It can also help regulate inflammation and boost your immune system by influencing the production of different immune molecules. In your skin, vitamin D can even help repair wounds and maintain a healthy barrier to protect against infection.
So even though we often think of vitamin D as necessary just for bone health, it's involved in many different processes throughout the body thanks to its ability to activate these receptors.
Sources of vitamin D
Our bodies receive vitamin D through three primary sources: sunlight, food and supplements. Exposure to sunlight triggers our bodies to produce vitamin D, but factors like time of day, skin color and sunscreen use can affect how much vitamin D we make. In general, it's recommended that people get around 10-30 minutes of sunlight exposure a few times a week to maintain adequate levels. It's important to note that excessive sun exposure can increase our risk of skin damage and skin cancer, so finding a balance is key.
Food sources of vitamin D include fatty fish, egg yolks and fortified foods like milk and cereal. But it can be challenging to consume enough vitamin D through diet alone. For example, a serving of salmon only contains around 400-500 IU of vitamin D, which is less than the recommended daily intake for most people. As a result, many people turn to supplements to boost vitamin D levels, but the type of supplement you choose matters.
Recent research has shown that vitamins D and K work synergistically to support bone and cardiovascular health. Studies have found that supplements with vitamins D and K are more effective in improving bone density and reducing the risk of fractures than supplementation with either vitamin alone. Additionally, vitamin K has been shown to enhance vitamin D absorption in the body, increasing its effectiveness.
Vitamin D deficiency
Despite the importance of vitamin D to our health, many people need more of this essential nutrient. Causes of deficiency can include limited sun exposure, limited dietary sources of vitamin D and medical conditions that interfere with absorption. For example, people with celiac disease, Crohn's disease and cystic fibrosis are more likely to experience vitamin D deficiency.
Vitamin D deficiency symptoms can be vague and include fatigue, muscle weakness, bone pain and a weakened immune system, which can harm our overall health.
Diagnosing a vitamin D deficiency requires a blood test to measure the vitamin D levels in the body. These levels are recorded in nanomoles per liter (nmol/L) or nanograms per milliliter (ng/mL). The National Institutes of Health recommends a blood level of at least 20 ng/mL (50 nmol/L) for general health, although some experts suggest that optimal levels may be higher. If you're concerned about your vitamin D levels, talk to your healthcare provider, who can recommend a blood test and suggest ways to boost your vitamin D intake, such as supplements or dietary changes.
Vitamin D is a crucial nutrient that plays a vital role in several bodily functions. To ensure you're getting enough vitamin D, consider safely increasing your sun exposure, eating more foods that contain vitamin D and adding a supplement with vitamins D and K if necessary. By prioritizing your vitamin D intake, you can support your body's health and function for years to come.
Justin Marsh is the founder and CEO of Arthur Andrew Medical, a manufacturer of enzyme and probiotic-based dietary supplements, headquartered in Scottsdale.