Muscle soreness two to three days after an intense workout or following strenuous physical activity is normal; however, sore muscles can also be an indication of vitamin D deficiency. This fat-soluble vitamin is processed through your skin via ultraviolet rays of the sun and present in a small selection of foods such as oily fish, dairy and fortified cereals, bread and orange juice. Vitamin D is essential for neuromuscular health, immune system function, mental health and emotional well-being.
Muscle Weakness and Bone Pain
Vitamin D assists in the absorption of calcium, which is central to bone health and safeguarding against rickets in the young and osteoporosis in the elderly. Merck Manuals lists muscle soreness as a symptom of vitamin D deficiency, along with muscle weakness and bone pain, adding that these symptoms can occur at any age. Tetany, another symptom arising from vitamin D deficiency, is characterized by a succession of painful muscle cramps. These cramps are caused by intensified neuromuscular activity and can result from hypocalcemia, alkalosis or hypomagnesemia.
The Sun and Vitamin D
The sun is a primary source of vitamin D. Ultraviolet rays penetrate the epidermal layer of your skin to stimulate production of vitamin D, which is then stored in your liver and fat cells. You are more susceptible to vitamin D deficiencies if your skin has a high degree of melanin and you live further away from the equator. Skin with less melanin absorbs higher levels of ultraviolet rays, allowing a greater amount of vitamin D to be processed. Despite this fact, Caucasians are still more vulnerable to osteoporosis in comparison to people of African descent, according to the Office of Dietary Supplements.
Reduced Sun Exposure
Seasonal factors, the time of day and length of time spent in the sun determines the amount of vitamin D your body receives and synthesizes. Environmental pollution should also be considered, as it creates a barrier between yourself and the sun and reduces exposure to sunlight, which in turn has an effect on vitamin D levels. Lifestyle also has a direct impact on sunlight exposure and vitamin D levels. People who spend less time out in nature and more time inside the house, driving in cars, working in office blocks and buildings, or shopping in malls get less sunlight. Although sunscreens are recommended, especially for those with less melanin, a sun protection factor of eight or more will block out a considerable amount of ultraviolet rays, again reducing vitamin D synthesis and levels.
Vitamin D is present in a small number of foods such as oily fish like sardines, salmon, mackerel and dairy foods such as milk and eggs taken from chickens nourished with vitamin D. Vegetarians can get vitamin D through dairy, and vegans can get it through consuming enriched foods like bread, cereals and fortified soya milk. Vitamin D supplements can also boost your levels if you are not getting enough through your diet. The US Food and Drug Administration recommends 400 international units of vitamin D, based on a 2,000 caloric daily intake.