You need vitamin D to maintain the correct levels of phosphorus and calcium in your blood. It also helps with the absorption of calcium, which your body needs for bone health. You are at risk of vitamin D deficiency if you have limited sun exposure, are obese, are elderly or have fat malabsorption syndrome as occurs with certain conditions like Crohn's disease. Lack of vitamin D can adversely affect your bone health. There are numerous signs that you are not getting enough vitamin D. If you suspect this is the case, consult a doctor before increasing your dietary intake because there is a risk of vitamin D toxicity.
Muscle Weakness and Pain
When you do not get enough vitamin D, you can experience muscle weakness and pain. For example, a study published in 2003 found that some 93 percent of 150 patients who came to the primary care facility Community University Health Care Center in Minneapolis, Minnesota, for nonspecific muscle pain were deficient in vitamin D. The study recorded vitamin D levels of patients admitted to the center for muscle pain for two years. The study researchers recommend screening patients who complain about muscle pain for a vitamin D deficiency as a standard practice.
You may have elevated parathyroid hormone levels if you are deficient in vitamin D. When you are deficient in this vitamin, your body cannot increase calcium absorption enough to meet your body’s needs. Your body’s solution is to increase parathyroid hormone production to mobilize calcium from your skeleton. This helps your body maintain normal concentrations of calcium in your blood. This condition is called secondary hyperparathyroidism; symptoms include bone deformities, broken bones and fractures, and swollen joints.
Over time, vitamin D deficiency leads to bone pain and soft bones, a condition called osteomalacia. Though your bones don’t continue to grow when you reach adulthood, they are constantly in a state of turnover; this is called remodeling. When you are deficient in vitamin D, you suffer progressive bone mineral loss. Bone pain will likely be subtle and go undetected in the initial stages, according to the U.S. Office of Dietary Supplements. Bone density loss, in the long term can lead to osteoporosis and increased risk for fractures. In children whose bones are growing, chronic vitamin D deficiency leads to the failure of bone mineralization and rickets, characterized by skeletal deformities and soft bones.
Fatigue or Headache
If you are suffering from fatigue or a headache, low vitamin D levels may be the cause according to a study published in September 2010 in the “Scandinavian Journal of Primary Health Care.” Such symptoms may accompany muscle pain. A case study published in December 2010 in the “Journal of Clinical Sleep Medicine,” also points to vitamin D deficiency as a possible cause for excessive daytime sleepiness. More research is needed, however, before routinely screening for low vitamin D should be recommended for this condition, notes study author D.E. McCarty.