Vitamin D Deficiency

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Original Editors -Nicole Hess & Shannon McMullen from Bellarmine University's Pathophysiology of Complex Patient Problems project.

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Definition/Description

Vitamin D, also known as calcidiol or 25(OH)D, is a fat-soluble vitamin obtained from sun exposure, food, and supplements. It is not naturally present in many foods but is often used to fortify food or taken as a dietary supplement.Vitamin D is synthesized in the body when cholesterol (7-dehydrocholesterol) activates with UVB rays from sunlight. When ingested the intestines absorbs the vitamin and sends it to the liver and kidneys for further processing. In the liver it converts to 25-hydroxyvitamin D [25(OH)D], also known as calcidiol and in the kidneys it forms the physiologically active 1,25-dihydroxyvitamin D [1,25(OH)2D], also known as calcitriol. It is a necessary vitamin for calcium absorption, maintaining serum calcium and phosphate concentrations to enable normal mineralization of bone and to prevent hypocalcemic tetany. It is also needed for bone growth and bone remodeling by osteoblasts and osteoclasts. Inadequate amounts of vitamin D is most commonly associated with rickets in children and osteomalacia in adults.

Prevalence

A minimum of 25% up to 50% US adult population are vitamin D deficient. According to a recent National Health and Nutrition Examination Survey, overall prevalence rate of vitamin D deficiency is approximately 41% in the US adult population. Regarding ethnicity, deficiency is most commonly seen in African Americans followed by Hispanics. UVB rays are absorbed by the melanin in people with darker skin tones; therefore, having a significant reduction of synthesis.

Other common characteristics associated with increased prevalence:

• Geriatric population
• Infants
• People with limited sun exposure
• Fat malabsorption
  
• Obesity (all ages): fat soluable vitamin is easily stored in adipose tissues --> decrease vitamin D in bloodstream
• Gestational diabetes
• Poor general health status
• Hypertension
• Insufficient daily intake of milk or other vitamin D containing foods
• Depression
• Burn patients

Characteristics/Clinical Presentation

Adults generally present with the diagnosis of osteomalacia, which may include the following signs and symptoms:

• General muscle weakness
• Falls
• Fractures
• Severe bone pain
• Myalgia
• Decreased functional status
• Decreased progress during rehabilitation

Children typically present with rickets as their diagnosis, which may include the following signs and symptoms:

• Bowing of the long bones
• Widening, fraying, and clubbing in areas of active bone growth, predominantly around the metaphyseal ends of the long bones and sternal ends of the ribs.
  

Associated Co-morbidities

Osteoporosis
The hormone 7-dehydrocholesterol decreases in the skin as a person ages. By age 65, approximately only 25% of it remains in the body, leading to decreased synthesis of vitamin D and therefore calcium absorption.

Skeletal Deformities
In children with rickets there is often bowing of the long bones and widening, fraying, and clubbing near epiphyseal (growth) plates. Predominant areas include metaphysis of the long bones and sterna ends of the ribs, which is also known as rachitic rosary.

Electrolyte Imbalance
Often associated with hypomagnesemia

Hyperparathyroidism

Cancer
Vitamin D may play a role in the prevention of colon, prostate, and breast cancers. The lack therefore may indicate possible increase of cancer risk. Research is often conflicting in this area.

Myofascial Trigger Points/Myalgia

Other potential comorbidities
Diabetes (type I and II), Insulin Intolerance, Hypertension, and Multiple Sclerosis

Medications

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Diagnostic Tests/Lab Tests/Lab Values

A risk marker used to measure defficiency levels is the plasma metabolite of Vitamine D, 25-hydroxyvitamin D (25(OH)D)

Various methods available to measure 25OHD concentration include:

• Competitive Protein Binding Assay (CPBA)
• Radioimmunoassay (RIA)
• Enzyme-linked Immunoassay (EIA, ELISA)
• Random Access Automated Assay using chemiluminescence technology (RAAA)
• High-Performance Liquid Chromatography (HPLC)
• Liquid Chromatography-mass Spectrometry (LC-MS)
• 24-hour Urine Calcium Excretion
  

Etiology/Causes

Adults

Primary causes include: inadequate sun exposure, insufficient supplementation, pregnant/lactating, and obesity.

Children and Adolescents

Main causes include: inadequate sun exposure, inadequate vitamin supplementation, and breastfeeding without vitamin D supplementation

Other Causes

• Low intake of vitamin D in diet 
• Poor renal function: reduces conversion of 25OHD to active metabolite in kidney 
  
• Intestinal malabsorption problems, often associated with aging ; Irritable Bowel Syndrome (IBS)
• Long-term uses of anticonvulsants, which accelerates breakdown of the active forms of vitamin D
• Autoimmune disorders: helper T cells (Th), a key componenet to antigen-specific immunity, is misdirected. Th cells (1 and 2) have vitamin D receptors on them, which  assist in suppressing the autoimmune disease --> vitamin D cannot bind with misdirected Th cells and also cannot assist in suppression of the disease (cyclic)
  
  

Systemic Involvement

1. Musculoskeletal System: Severe vitamin D deficiency may be associated with non-specific musculoskeletal pain, causing bone, muscle, and/or joint pain. When there is a vitamin D deficiency present, there is lack of suppression of autoimmune disorders, through Th1 cells. Common autoimmune disorders may include: RA and MS. Also, there are vitamin D receptors on skeletal muscle. When deficiency present, there is an associated increased risk of falls.
2. Endocrine System: Parathyroid hormone (PTH) is a key hormone that regulates renal synthesis of 25OHD, which therefore maintains calcium ions in the blood. PTH rises and stimulates 25OHD synthesis when the concentration of calcium ions in the blood fall. Through this mechanism, the active vitamin D metabolite, 25OHD, promotes calcium supply to the bloodstream. As the cascade progresses, parathyroid is overstimulated, causing secondary hyperparathyroidism. 
3. Cardiovascular System: Research sugggests that low vitamin D may be a risk factor for certain arterial diseases such as Peripheral Artery Disease, Congestive Heart Failure, and Aortic Aneurysms. It may also contribute to decreased protection over lung function and increase lung functional decline in smokers. Vitamin D may have an affect on cardiac contractility, vascular tone, and cardiac tissue maturation due to the vitamin D receptors on the heart muscle. Therefore, vitamin D may play a role in the pathogenesis of CV problems.
4. Gastrointestinal: Due to vitamin D receptors' presence in colon tissues, vitamin D receptors play a role in the proliferation of cells and their response to stimuli. Therefore, a deficiency in vitamin D may play a role in colon cancer. Also as mentioned before, there is a lack of suppression of autoimmune diseases, such as Irritable Bowel Syndrome (IBS) when a vitamin D deficiency is present.
5. Psychosocial System: Low levels of vitamin D are associated with depression.
6. Integumentary: In the literature, children with burns are at risk of furthering or contracting a vitamin D deficiency and its associated side effects due to low sun exposure. There are no current research has been conducted on adults.

Medical Management (current best evidence)

Diagnosis:

Though vitamin D deficiency is prevalent, serum testing of vitamin D deficiency is not universally suported due to expenses, so other tests are administered as described above. 

• Some clinicians may administer bone decalcification testing, which is done through medical imaging. (Refer to Diagnostic Tests)
  
• Low vitamin D serum levels are categorized into insufficiency, and the more severe deficiency:

                                                                       Serum levels of vitamin D:

Insufficiency 25(OH)D	21-29 ng/mL
Deficiency 25(OH)D	<20 ng/mL

 

Treatment:

Due to low availability of foods with adequate vitamin D, treatment is largely based on supplements and dietary modifications as follows:

• Supplementation with 800 to 1000 IU/d of vitamin D
• Or less than 2000 IU/d to avoid toxicity for those 1 year and older   

                                         Recommended Dietary Allowances (RDA's) for Vitamin D

Age	Male	Female	Pregnancy
0-12 months*	400 IU (10 mcg)	400 IU (10 mcg)
1-13 years	600 IU (15 mcg)	600 IU (15 mcg)
14-18 years	600 IU (15 mcg)	600 IU (15 mcg)	600 IU (15 mcg)
19-50 years	600 IU (15 mcg)	600 IU (15 mcg)	600 IU (15 mcg)
51-71 yeas	600 IU (15 mcg)	600 IU (15 mcg)
> 70 years	800 IU  (20 mcg)	800 IU (20 mcg)

Sunlight Exposure Recommendations

      To maintain sufficient serum vitamin D level, the National Institutes of Health (NIH) recommends 10 to 15 minutes of direct          sunlight at least twice a week.

Physical Therapy Management (current best evidence)

There are no direct physical therapy interventions for vitamin D deficiency. Patient will be referred to physical therapy for treatment of impairments that may be a cause of vitamin D deficiency such as decline in muscle strength, decline in physical functioning, or falls prevention. (See Clinical Presentation)

Physical therapists can take a team approach with medical management through patient education on:

• Foods high in vitamin D
• Importance of following medical recommendations for vitamin D intake
• Importance of proper sun exposure with risks of overexposure

Alternative/Holistic Management (current best evidence)

Vitamin D is best treated with holistic methods such as foods high in vitamin D and sun exposure

Adequate Sources of Intake:

• D2 (ergocalciferol) is found in vegetable sources and oral supplements
  
• D3 (cholecalciferol) is obtained primarily from skin exposure to ultraviolet B (UVB) radiation in sunlight, ingestion of food sources such as oily fish and variably fortified foods (milk, juices, margarines, yogurts, cereals, and soy), and oral supplements
  

Most foods contain between 50 and 200 IU per serving, which varies depending on geographical location and use of th fortification process

Food Sources Containing Vitamin D

Food	IUs per Serving*	Percent DV**
Cod live oil, 1 tablespoon	1,360	340
Swordfish, cooked, 3 ounces	566	142
Salmon (sockeye), cooked, 3 ounces	447	112
Tuna fish, canned in water, drained, 3 ounces	154	39
Orange juice fortified with vitamin D, 1 cup	137	34
Milk, nonfat, reduced fat, and whole, vitamin D fortified, 1 cup	115-124	29-31
Yogurt, fortified with 20% of the DV of vitamin D, 6 ounces	80	20
Margarine, fortified, 1 tablespoon	60	15
Sardines, canned in oil, drained, 2 sardines	46	12
Liver, beef, cooked, 3 ounces	42	11
Egg, 1 large (vitamin D found in yolk)	41	10
Cheese, Swiss, 1 ounce	6	2

IUs= International Units

DV= Daily Values developed by U.S. Food and Drug Administration

Proper sun exposure:

• Cloud coverage can decrease absorption by as much as 50%
• Sun through windows is inadequate-Glass blocks the synthesis process
• Sunscreen may block synthesis if over the entire body
• Get 5-30 minutes twice per week between 10AM - 3PM without sunscreen
• Best exposure spots: face, arms, legs, and back
• Tanning beds emit 2-6% UVB (not medically recommended source)
• limit sun exposure without sunscreen to decrease risk of fatal cancers
  

Differential Diagnosis

• Fibromyalgia 
• Rheumatic diseases 
• Polymyositis
• Muscular Dystrophy

Case Reports

Case Report #1  [Full article available at www.najms.org/article.asp] 

Authors:
Clement Z, Ashford M, and Sivakumaran

Abstract:

• Vitamin D deficiency is extremely common in multiple myeloma, and it represents a surrogate for clinical multiple myeloma disease status. Patients may complain of dull, persistent, generalized musculoskeletal aches and pains with fatigue or decrease in muscle strength.
• This case highlights that vitamin D deficiency is common in patients with multiple myeloma, and can cause generalized musculoskeletal pain and increase the risk of falls, yet it often goes unrecognized. In patients with non-specific musculoskeletal pain, and inadequate sun-exposure medical practitioners must have a high index of suspicion for vitamin D deficiency.
  

Patient Characteristics:

• 63 year old man with multiple myeloma
• Current reactivation of herpes zoster
  

Subjective: Chief complaints include:

• Generalized weakness
• Nonspecific musculoskeletal pain
• Reported multiple falls
  

Examination:

• Pale presentation with a depressed affect
•  Resting tremor, generalized bony tenderness, worse on movement and weight bearing
• Muscle weakness
• Waddling gait
• Bone studies showed features of osteomalacia with a very low Vitamin D level of less than 20 nmol/L
  

Past Medical History:

• Previously diagnosed with solitary plasmacytoma in 2001, which then progressed to smoldering myeloma in 2004
• 2007 the indolent version of his myeloma transformed to a more aggressive form of myeloma with non-specific musculoskeletal chest pain, anorexia, weight loss, and tumour-lysis requiring hospital admission and plasmapheresis.
• June 2010 the patient was admitted to hospital after multiple falls and zoster reactivation including ophthalmic zoster of the right first and second trigeminal branches.
  

Intervention: Physical Therapy

Co-intervention: Received 3,000 nmol/L daily of Vitamin D supplementation
Outcomes: 4 months later

• Significant decrease in his generalized musculoskeletal pain
• Bloods showed a normalized level of Vitamin D of 109 nmol/L
• Decrease in alkaline phosphatase to 182 U/L
• Currently undergoing palliative rehabilitation.

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Resources

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Recent Related Research (from Pubmed)

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References

Goodman C, Snyder T. Differential Diagnosis for Physical Therapist: Screening For Referral. Missouri: Saunders Elsevier; 2013.

Goodman C, Fuller K. Pathology: Implications for the Physical Therapist. 3rd ed. Missouri: Saunders Elsevier; 2009.

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