Vitamin D deficiency and Chronic muscle pain

Introduction:

Chronic widespread muscle pain is very prevalent in general population. Many studies have been done to identify its reason and hypovitaminosis d is one of the major cause of chronic muscle pain. Deficiency of vitamin d causes not only muscle pain but also ricktets in children, osteomalacia.

It is a fat soluble vitamin which helps in absorption and metabolism of calcium and phosphorus.It is biologically inert and its  active form is called Calcitriol (1,25-Dihydroxycholecalciferol). Body synthesizes it from cholesterol when sun exposure is adequate. Hence  it is also known as the “sunshine vitamin“.It  can also be ingested as cholecalciferol (vitamin D₃) or ergocalciferol (vitamin D₂) .

Sources:

• Adequate sunlight exposure
• flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources
•  beef liver, cheese, egg yolks, fortified milk

Synthesis:

Recommended Daily Allowance:

Infants 0-6 months 400 IU*

Infants 7-12 months 400 IU*

Children 1-3 years 600 IU

Children 4-8 years 600 IU

Children/Adults 9-70 years 600 IU

Adults more than 70 years 800 IU

Pregnancy & Lactation 600 IU

Hypervitaminosis D

Regular intake of more than 1250 micrograms/day (50,000 IU) can produce overt toxicity after several months. Vitamin D overdose causes hypercalcemia, anorexia, nausea, vomiting,weakness, insomnia, pruritus and sometimes renal failure. Treatment of hypervitaminosis D is discontinuation if intake of vitamin d and calcium supplements.  But exposure to sunlight for extended periods of time does not normally cause vitamin D toxicity.

Symptoms of Hypovitaminosis D:

Chronic muscle pain lasting for more than 3 months

Easy fatigability

Muscle weakness

Low bone mineral density

Pathological fracture

Our research on 2000 Nepalese patients with muscle pains showed deficient vitamin D levels in 90 percent of them. This shows that this is prevalent even in our country.

Diagnosis:

–       Symptoms

–       Serum 25 OH cholecalciferol level

Categories:

Sufficient: 30-100 ng/ml

Insufficiency: 20-29 ng/ml

Mild Deficiency: <20 ng/ml

Severe: <10 ng/dl

Who should be tested for hypovitaminosis D?

Patients with inadequate sun light exposure or intake

History of chronic muscle pain

Elderly

Malabsorption

Chronic kidney disease

 

Treatment:

Patients with 25OHD level < 30 ng/dl should be treated with oral supplementation of cholecalciferol to be taken 6 lakh IU once a week for 8 weeks and then maintenance dose of once a month for 6 – 8 months.Calcium supplementation can also be added while taking vitamin d supplements. Vitamin D level can be repeated after 6 months of treatment. If the level is corrected (>30 ng/dl), cholecalciferol supplementation can be taken once a month for years, whereas if the level is not corrected even after taking supplementation for 6 months, parenteral vitamin d should be administered ( 6 lakh IU IM once a year). If the patients don’t respond to parenteral vitamin d too, other causes of chronic muscle pain like fibromyalgia should be considered and managed accordingly.

  

Authors:
Dr Binit Vaidya,
MD(AIIMS), FACR
Alka Hospital
Jiwanta Swasthya Sewa Sadan (01-4303010)

 

Dr Shweta Nakarmi,
MBBS, MD Resident