Vitamin D Deficiency: Rickets and Osteomalacia
Vitamin D deficiency leads to defective mineralization of bone matrix, presenting as Rickets in children (growth plates affected) and Osteomalacia in adults (bone matrix affected).
1. Clinical Features in Children (Rickets)
| Region | Characteristic Finding |
|---|---|
| Skull | Craniotabes (softening), frontal bossing, delayed fontanelle closure. |
| Thorax | Rachitic rosary, Harrison groove, pigeon chest deformity. |
| Extremities | Widening of wrists/ankles, bowing of legs (genu varum/valgum). |
2. Systemic & Biochemical Features
- Musculoskeletal: Proximal muscle weakness, hypotonia, and bone pain.
- Biochemistry: Low serum 25-hydroxyvitamin D, low or normal calcium, low phosphorus, and elevated Alkaline Phosphatase (ALP).
3. Clinical Pearls
- Hypocalcemic Seizures: Severe vitamin D deficiency in infants can present with symptomatic hypocalcemia, including tetany and seizures.
- Osteomalacia in Adults: Often presents as diffuse, persistent bone pain (pseudofractures or Looser zones on imaging).
NEET PG Hint: Remember that Craniotabes is the earliest clinical sign of rickets in infants. Do not confuse it with the physiological softening of the skull. Always check serum ALP as it is the most sensitive marker for early diagnosis.