Vitamin D refers to two different forms of this vitamin: vitamin D-2 and vitamin D-3. Vitamin D-3 is synthesized when skin absorbs sunlight, while vitamin D-2 is made by plants. Your body converts both forms into the same hormone, so they fill the same roles and they are referred to collectively as vitamin D. Since the primary role of vitamin D is to enable calcium absorption, signs of a deficiency often appear in your bones.
Bone And Muscle Weakness
If you lack an adequate amount of vitamin D, your body can't absorb enough calcium. This has a double impact on your bones. For starters, you won't have enough calcium to maintain healthy bones. But calcium has other vital jobs to fill, such as maintaining muscle contractions in your heart. When calcium is low, your body takes it away from your bones to fill its other roles. As a result, vitamin D deficiency causes a loss of bone density, which leads to bone pain, weak bones and an increased risk for osteoporosis. Muscle weakness and aches may also indicate a vitamin D deficiency since vitamin D may help maintain muscle strength.
Lowered Immune Response
Vitamin D plays an important role in maintaining an adequate immune response in the body. It regulates proteins that kill bacteria and stimulates the growth of white blood cells that destroy invading pathogens. A vitamin-D weakened immune system is associated with an increased risk of flu. Inadequate vitamin D is also involved with serious autoimmune disorders such as arthritis, multiple sclerosis and Type 1 diabetes, according to the Linus Pauling Institute.
Depression And Cognitive Problems
According to Women To Women, depression and mood swings may be symptoms of vitamin D deficiency. Chronic fatigue is a common byproduct of low vitamin D and this may contribute to irritability or a low mood in people. Older people may experience disorganized thought patterns and have difficulty with concentration or memory. These cognitive challenges may indicate low vitamin D2 levels. Adequate vitamin D may help stabilize energy, mood and cognition to healthy levels.
Sources and Recommendations
Mushrooms are the primary source of vitamin D-2. They contain a substance -- ergosterol -- that turns into vitamin D-2 when exposed to sunlight. The amount of vitamin D-2 varies significantly from one mushroom to the next, but some producers purposefully expose mushrooms to ultraviolet light to boost their D-2 levels. Vitamin D-2 is also synthetically produced for use in supplements. In any form, vitamin D does not naturally occur in most foods. Fatty fish, such as salmon and mackerel, contain vitamin D-3. Otherwise, most people get vitamin D from fortified milk and other foods. You should consume 600 international units, or 15 micrograms, of vitamin D daily.