Vitamin D is not a true vitamin. By definition, vitamins must be consumed through the diet or other external sources. Most mammals, including humans, are able to synthesize vitamin D through the conversion of cholesterol in the bloodstream. This process happens naturally when an individual spends time in the sun. Unfortunately, people in modern times often suffer from a lack of vitamin D as modern lifestyles often shield people from the sun. Understanding what this vital substance does and how to get enough of it in your body will help prevent the symptoms of vitamin D deficiency.

What Does Vitamin D Do?

The primary function of vitamin D is maintaining blood calcium and phosphorus levels by helping the body absorb these nutrients from food. Recent research indicates that vitamin D may also play an important role in maintaining immune system health. Vitamin D may help prevent cancer and autoimmune diseases. It’s also a vital nutrient in guarding against osteoarthritis and other bone diseases.

Symptoms of Vitamin D Deficiency

The most acute expressions of vitamin D deficiency are rickets and osteomalacia. Rickets develops in infants and children and causes bone weakness and deformity. Osteomalacia usually develops later in an adult’s life. It causes a loss of bone density and general muscular weakness. Both conditions can be devastating if left untreated.

Fortunately, vitamin D deficiency is usually corrected before it reaches this level. Since most milk is fortified with vitamin D, people who consume dairy products generally have enough vitamin D to prevent these severe disorders. This may not be enough of the vitamin to promote optimal health, however, and a higher quantity of vitamin D will have a positive affect on your overall vitality.

People who experience vitamin D deficiency are at greater risk for cardiovascular disease. Asthma, cancer, cognitive impairment, multiple sclerosis and diabetes have all been linked to vitamin D deficiency.

Certain people are at higher risk of being deficient in vitamin D:

  • Vegans and others who do not eat meat, dairy or fish
  • Individuals living in northerly climates where sunlight is limited
  • People with Crohn’s disease or other disorders that disrupt the absorption of nutrients from food
  • Elderly people or those who are home-bound by disease or disability
  • Shift workers or others who spend very little time in the sun

Additionally, obesity is a major cause of vitamin D deficiency. The body naturally pulls vitamin D from fat cells in order to release them into the bloodstream. In people with a BMI of 30 or above, however, this becomes more difficult. This causes more vitamin D to be locked inside cells rather than becoming released into the system.

Sources of Vitamin D

The minimum daily requirement for vitamin D is 400 IUs for elderly people and just 200 IUs for people under 50. This is roughly equal to the vitamin D received from 10 to 20 minutes of sun exposure or two to four glasses of fortified milk. Doctors now recommend a much higher dose whenever possible, however, and most people fall well below the ideal levels of vitamin D. The upper limit of daily vitamin D consumption is 4,000 IUs, and most doctors currently recommend that between 800 and 1,000 IUs per day is ideal.

There are several sources of vitamin D, and obtaining the vitamin from multiple different sources is the best way to ensure you’re getting enough of it. Here are the most common sources of vitamin D:

– The Sun -  Synthesizing your own vitamin D is the easiest and fastest way to increase the amount of vitamin D in your system. The UV radiation in the sun is responsible for triggering the synthesis of vitamin D. If you currently don’t spend much time outside, try to find ways to increase the time spent outdoors. Change your morning exercise routine to a walk around the block instead of a half-hour on the treadmill, for example, or take your lunch outside rather than eating in the office. Just 30 minutes of sunlight a day can stave off most vitamin D deficiencies.

– Fortified Foods – Milk is the primary source of vitamin D for many people. If you don’t drink milk, look for other fortified foods that can provide your recommended dose of vitamin D. Some orange juice brands, for example, are fortified with calcium and vitamin D. Vegan milk alternatives like soy milk or almond milk may also be fortified. Many breakfast cereals and other grains are also fortified with vitamin D; just check the label to see what nutrients an enriched cereal will provide.

– Natural Sources – Fatty fish is the best natural source of vitamin D. Tuna, mackeral and salmon are all excellent sources of this essential nutrient. They’re also a good source of the healthy omega-3 fatty acids that have been linked to so many positive health benefits in the past few years. Look for a way to increase your fish intake to promote your overall well-being.

– Supplements – In addition to dietary sources, vitamin D can be taken as a supplement or as part of a regular multi-vitamin. These supplements may not be absorbed as easily as dietary sources, but they are a great choice for people who still have a difficulty getting enough of the vitamin through other means.

Obtaining the proper amount of vitamins and other nutrients in your diet can be challenging, but it shouldn’t be impossible. If you’re concerned about your vitamin D intake, be sure to discuss your situation with a doctor to see whether supplements are the right choice for you. Striving to eat a healthy diet and get ample amounts of sun will also ensure you keep a healthy life.