Vitamin D is a collection of five fat-soluble substances that are essential for healthy bone growth and maintenance, strong immunity and mood regulation. Lack of necessary vitamin D is common among Americans, with estimates of up to 80 percent of some groups being deficient, according to "Contemporary Nutrition: Functional Approach" (2009). Vitamin D-3 is the most physiologically important form and is produced within skin in response to specific UV-B radiation from sunshine. Lack of sunshine often leads to vitamin D deficiency and characteristic side effects.
Recommendations and Deficiency
The National Institutes of Health currently recommends 400 IU of vitamin D per day for infants, 600 IU for adults up to the age of 70 and 800 IU for adults beyond 70 years of age. These recommendations are meant to avoid overt deficiency side effects, although some medical authorities suggest that at least 1,000 IU daily are required to promote health. Vitamin D is not common in food, although products such as milk, orange juice and cereals, are often fortified with it. The primary cause of vitamin D deficiency is lack of appropriate sun exposure, which is even more common in higher latitudes. African Americans have the highest rates of vitamin D deficiency because their skin is less efficient at synthesizing it. Indoor lifestyles, concerns of skin cancer and use of sun screens prevent people from getting enough sunshine.
Initial Side Effects
The National Institutes of Health states that serum concentration of calcidiol is the best measure of vitamin D status, and that amounts less than 37.5 nmol/L are considered deficient. The early signs of vitamin D deficiency may take many months to develop, but often include heavy sweating, heightened anxiety, fatigue not resolved by sleep, poor sleep, reduced appetite, mild depression and muscle cramps.
Side Effects on Bones
It is well documented that severe vitamin D deficiency leads to rickets, or soft bones, in children and osteomalacia in adults, which involves painful bone deformations, as cited in "Human Biochemistry and Disease." Bowed legs and spinal "humps" are characteristic of both conditions. Vitamin D deficiency also contributes to osteoporosis and reduced muscle strength, both of which increase the risk of falls and bone fractures in people as they age.
Side Effects on Muscles
Other musculoskeletal disorders, such as muscle wasting and chronic back pain, have also been associated with vitamin D deficiency. An Egyptian study published in the March 2007 edition of "Clinical Rheumatology" indicated that chronic, low back muscle pain lasting more than three months was associated with significantly lower vitamin D intake.
Side Effects on Mood and Cognition
Lack of sun exposure has been linked to a depressive state known as seasonal affective disorder (SAD) and the underlying cause may be lack of vitamin D, according to "Professional Guide to Diseases." Depression and reduced cognition have been linked to vitamin D deficiency in some studies, especially those involving the elderly. A study of older men, half of which had mild degrees of Alzheimer's disease, was published in the December 2006 edition of the "American Journal of Geriatric Psychiatry" and noted that vitamin D deficiency was linked to depressed mood and reduced performance on 50 percent of the cognitive tests.
References
- "Contemporary Nutrition: Functional Approach"; Gordon M. Wardlaw; 2009
- The National Institutes of Health: Office of Dietary Supplements: Vitamin D Fact Sheet
- "Human Biochemistry and Disease"; Gerald Litwack; 2008
- "Clinical Rheumatology"; Hypovitaminosis D in Female Patients with Chronic Low Back Pain; A. Lotfi et al.; March 2007
- "Professional Guide to Diseases: Ninth Edition"; Springhouse Publishing; 2009
- "American Journal of Geriatric Psychiatry"; Vitamin D Deficiency is Associated with Low Mood and Worse Cognitive Performance in Older Adults; C. Wilkins et al.; December 2006
Member Comments