Rickets of Vitamin D Deficiency

The Second Affiliated Hospital of Shantou University Medical College

Ma Lian

Review

Rickets ： signifying a failure in inernalization of growing bone or osteoid tissue.

Failure of mature bone to mineralize is called osteomalacia.

Etiology Inadequate direct exposure to ultraviolet rays

in sunlight Inadequate intake of vitD (diet may contain litt

le vitD) Growth drug Disease:hepatic and renal lesions 、 celiac dis

ease 、 steatorrhea or cystic fibrosis

Or both

About Vitamin-D Two forms : vitD2 /vitD3 vitD2 :most as irradiated ergosterol,largely r

eplaced the fish liver oils as source vitD3 :available in human skin as 7-dehydro

cholesterol. both are hydroxylated in the liver to 25 － (O

H)2D in the renal to 1. 25 － (OH)2D: facilitate calci

um and phosphorus absorpted

Pathology

the epiphyseal plate of metaphysis is well demonstrated.

The cartilage cell is orderly

The calcified matrix forms the epiphyseal plate is regular

The degenerating cartilage, islands of capillaries, osteoblasts, and unmineralized osteoid compose of broad , irregular, rachitic imtermediate zone

Chemical pathology

can be conceptualized to be the body’s attempt to maintain normal serum calcium levels.

When calcium is lessparathormone is secretedincrease the calcium and phosphorus concentration

Alkaline phosphatase (ALP). (normal level ≦200IU/dL) can be 500UI/dL. But may be normal in infants who have rickets and who are protein or zinc depleted.

aminoaciduria, a decrease of citrate ,and its increased urinary excretion, decreased ability of the kidneys to make an acid urine, phosphaturia, and occasionally ,mellituria.

The parathyroid glands hypertrophy

Clinical manifestations

Early signs:

Increased sweating, particularly around the head ,which result in the occipital bone bare

Clinical manifestations

Advanced rickets: Head: early signs is cranio

tabes, Like a derby hat or

ping pong ball .

Thorax:

rachitic rosary

Harrison’s groove

Pigen breast deformity

children are late in standing and walking

The deformities of the long bones :knobbing and prominence of the epiphyses

Other manifestations:

Teeth-erupting may be delayed,the enamel and extensive aries are defected.

Muscle tone is poor

Roentgenographic findings

Diagnosis

The diagnosis is based on: a history of inadeuate intake of vitamin

D and on clinical observation; then confirmed chemically ; by roentgenographic examination .

Differential diagnosis

Scurvy: a ledgelike depression with the chondral or sternal portion is displaced below the osseous ribs.

Chondrodystrophy :irregular 、 concave outlines of the distal ends of the bones ,no roentgenographic evidence of fraying

Other epiphyseal lesions: congenital epiphyseal dysplasia,cytomegalic inclusion isease ,syphilis ,rubella ,and copper deficiency.

Bowlegs :maybe a familial characteristic. Vitamin D-resistant rickets and other metab

olic disturbances with osseous lesions resembling rickets

Complications

Respiratory infections :bronchitis and bronchopneumonia

pulmonary atelectasis Anemia due to iron deficiency or accom

panying infections

Treatment

Natural and artificial light oral administration of vitD(preferred) d

aily administration:vitD3:50-150 µg or 1.25(OH)-D: 0.5-2 µg (except vitD refractory rickets

Administering 15000 µg of vitamin D in a single dose without further therapy for several months may be advantageous. More rapid healing follows, possibly with earlier differential diagnosis from genetic vitamin D-resistant rickets .

Roentgn-ray appearance showing healing

A: active rickets B: healing after 27 day:

new line of calcification

C: after 34 day calcification line dense;periosteal calcification increase

D: complete healing after 3 months

Prognosis

If therapy is given in time , healing begins within a few days and progresses slowly until the normal bony structure is restored

It is not a fatal disease,but complications are more likely to cause death of rachitic children than normal children

Prevention

Can be prevented by exposure to ultraviolet light

Administered vitD :daily requirement of vitamin D is 10µg or 400IU

Vitamin D should also be administered to pregnant and lactating mothers