Vitamin D: Diseases associated with Vitamin D Deficiency Part 3

[BruceZ]

Hello everyone. First, I would like to repost the table that was in Part 2 of this series. I guess I should not write these pieces late at night! Please note the correction in the first column from the NIH Office of Dietary Supplements. I accidentally transposed the numbers for Sufficiency and Deficiency. This is the corrected version below.



What happens if a person has too little vitamin D?

It is known that vitamins are good for an individual; however, too little or too much may cause a problem. I am sure that many of you have had patients in the past who have told you that since they heard a certain vitamin or herb was good for them that they decided to double or even triple the dosage. Although this may not be harmful with some vitamins or herbal medications, it can be disastrous with others.

I just received my July 2010 issue of “Endocrine Today: Clinical News on Diabetes and Endocrine Disorders” (1) and the cover story is “Surge of information on benefits of vitamin D, but no interventional trial data exist yet to ensure safety.” The article, written by Angela Milone, goes on to state that there are over 1,000 studies examining the benefits of vitamin D http://www.clinicaltrials.gov from the years 1959-1999 there has been between 700-900 abstracts that have had the words “vitamin D” in the title or abstract; and just in 2009 there were more than 2,400 papers published on vitamin D! Current research such as the VITAL (Vitamin D and Omega-3 Trial) has been recently launched with JoAnn D. Manson, MD, DrPH as its principal investigator. This interventional trial with over 20,000 men and women registered will examine the effects of taking 2,000 IU/day of vitamin D as well as the role of vitamin D in disease prevention.

?? Reader Questions ??

• How much vitamin D do you usually prescribe to your patients when they show either a insufficiency or deficiency?
• Have you found any efficacy between vitamin D levels in preventing diseases among your patients?

Vitamin D Deficiency

As noted above, vitamin D deficiency is referred as having too little vitamin D in your body. Vitamin D deficiency is found most commonly among children and the elderly, especially those who are institutionalized, e.g., nursing homes, or who are hospitalized, in the United States. (2) As noted in the previous posts in this series, vitamin D deficiency occurs due to not being in or receiving enough sunlight, decreased intake of vitamin D whether this be due to decreased vitamin D in breast milk, malabsorption syndromes, or not ingesting foods that have vitamin D as part of their make-up as well as medications that decrease the absorption of vitamin D or decrease the efficacy of vitamin D. Lastly, according to Hollick, (3) there are over 1 billion individuals worldwide who have either vitamin D insufficiency or deficiency.

Rickets

“Rickets, a disease of growing bone, occurs in children only before fusion of the epiphyses, and is due to unmineralized matrix at the growth plates.” (4) Most of the clinical manifestations of rickets is found in the skeleton. Changes that can be felt or seen include craniotabes, a rachitic rosary of the ribs, growth plate widening, and /or a Harrison groove on the lower anterior chest. Besides the skeletal abnormalities, other complaints by the child or parents may include difficulty walking, weakness, and failure to thrive. Diagnosis is usually made by the classic radiographic abnormalities. “The initial laboratory tests in a child with rickets should include serum calcium; phosphorus; alkaline phosphatase; parathyroid hormone; 25-hydroxyvitamin D; 1, 25 dihydroxyvitamin D3; Creatinine; and electrolytes.” (4)

Osteomalacia
Ostomalacia is usually used for the adult population who has a defect in the mineralization of the bone. Osteomalacia is insidious compared to rickets in children. The radiographic features may be overlooked especially if a patient does not obtain x-rays. Symptoms may include diffuse skeletal pain and bony tenderness. (5) Additionally, patients may complain of hip pain, and/or muscular weakness. Fractures can occur even with minimal trauma including vertebral fractures with loss of height. Radiological features can be undistinguishable from those found in osteoporosis. A specific finding could be pseudofractures or Looser’s zones found usually on the inner aspect of the femur, the pelvis, outer edge of the scapula, upper fibula, and metatarsals. (5) It is suggested that the laboratory tests ordered for children with rickets be ordered for those with Osteomalacia. It is imperative to find the source of the Osteomalacia.

?? Reader Questions ??

• How would you treat an adult with Osteomalacia if you found someone in your practice with this deficiency of vitamin D?
• How often do you check vitamin D levels in your patients?

Part 4 will discuss how to treat vitamin D deficiency.

Bruce S. Zitkus, EdD, ARNP, ANP-BC, FNP-BC, CDE

References
1 Milone, A. (2010, July). Surge of information on benefits of vitamin D, but no interventional trial of data exist yet to ensure safety. Endocrine Today, 8(7):1 and 10-12.

2 Tangpricha, V., & Khazai, N.B. (2009). Vitamin D deficiency and related disorders. Emedicine fromWebMD. Retrieved from http://emedicine.medscape.com/article/128762-overview.

3 Holick, M. (2007). Vitamin D deficiency. New England Journal of Medicine, 357(3):266-281.

4 Greenbaum, L. (2007). Rickets and Hypervitaminosis D. In R.M. Kliegman, R.E. Behrman, H.B. Jenson, & B.F. Stanton (Eds.), Nelson Textbook of Pediatrics, (18th ed.), (pp. 253-263). Philadelphia, PA: Saunders Elsevier.

5 Bringhurst, F.R., Demay, M.B., Krane, S.M., Kronenberg , H.M., "Chapter 346. Bone and Mineral Metabolism in Health and Disease" (Chapter). Fauci, A.S., Braunwald, E., Kasper, D.L., Hauser, S.L., Longo, D.L., Jameson, J.L., Loscalzo, J.,: Harrison's Principles of Internal Medicine, 17e: http://www.accessmedicine.com/content.aspx?aID=2882031.