Indian Pediatr 2014;51: 1021-1022
Vitamin D Deficiency: An Uncommon Cause of
Chandrika Azad and *Sukhvinder Singh
Departments of Pediatrics, Government Medical College
and Hospital, Chandigarh; and *Department of Medicine, HS Judge
Institute of Dental Science and Hospital, Chandigarh.
Vitamin D deficiency can present with neuromuscular symptoms at all ages
from floppiness in infancy, delayed motor milestones in toddlers and
acquired proximal muscle weakness in adolescents and young adults.
Proximal limb myopathy associated with rickets is well known but truncal
weakness is rare .
A 6-year-old girl presented with progressive weakness
of body for six months and inability to get up from bed for two months.
She was a vegetarian and had an aversion to milk and milk products. She
received vigorous physiotherapy from a local hospital. At presentation,
child had stable vitals and had pallor. Her weight was 17.5 Kg, The
muscle bulk was normal, and power was MRC scale 3/5 at shoulder and hip
joints and 4/5 at distal joints. Truncal and neck muscles were severely
involved. Deep tendon reflexes were elicitable. There were no signs of
sensory involvement, meningeal irritation, cerebral dysfunction or
cranial nerve involvement. Wrist joints were widened. X-ray knee
joint showed cupping and fraying of lower end of femur, upper end of
tibia and fibula, and fracture of upper part of both fibulae; severe
osteopenia was present. Serum calcium was 7.0 mg/ dL, phosphorus 3.1 mg/dL
and alkaline phosphatase 2375 IU/L. Serum 25(OH) vitamin D levels were 5
ng/mL(normal 40-60 ng/mL) and Parathormone level was 70 pg/mL (normal
13-66 pg/mL). Serum electrolytes, renal and liver function tests,
thyroid function test and anti-tissue transglutaminase antibody levels
were within normal limits. Electromyography (EMG) could not be performed
as patient was not cooperative; Nerve-conduction in lower limbs was done
which was normal. She was given intramuscular injection of 600,000 IU of
vitamin D and started on calcium supplements (200mg/kg/day). Within a
week child started getting up from bed, and next week she was able to
walk without support.
Vitamin D probably exerts its actions on muscles
through two pathways. The genomic pathway affects calcium uptake,
phosphate transport and phospholipid metabolism as well as myoblast
differentiation and division involving de novo protein synthesis.
Non-genomic pathway affects calcium transport and contractility
Vitamin D deficiency is highly prevalent in Indian
population; sun exposure, atmospheric pollution, skin pigmentation,
dietary and genetic factors are important determinants for it .
Various disorders like malabsorption syndromes, chronic kidney and liver
disorders and drugs can also lead to vitamin D deficiency .
Recommended daily allowance (RDA) for vitamin D in children 1-13 years
of age is 600 IU/day . Poor dietary habits can lead to severe vitamin
D deficiency and its consequences even in the absence of pathological
causes. The need of the hour is to suspect vitamin D deficiency in motor
delay or muscle weakness and its prompt treatment.
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