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$Unique_ID{BRK04190}
$Pretitle{}
$Title{Rickets, Vitamin-D Deficiency}
$Subject{Rickets Vitamin-D Deficiency Nutritional Rickets Rickets Vitamin-D
Deficiency Rickets Fanconi's Syndrome Infantile Scurvy Lowe's Syndrome
Osteomalacia Pseudovitamin D Deficiency Rickets Hypophosphatemic Rickets }
$Volume{}
$Log{}

Copyright (C) 1992 National Organization for Rare Disorders, Inc.

883:
Rickets, Vitamin-D Deficiency

** IMPORTANT **
It is possible that the main title of the article (Vitamin-D Deficiency
Rickets) is not the name you expected.  Please check the SYNONYM listing to
find the alternate name and disorder subdivision covered by this article.

Synonyms

     Nutritional Rickets
     Rickets
     Vitamin-D Deficiency Rickets

Information on the following diseases can be found in the Related
Disorders section of this report:

     Fanconi's Syndrome
     Infantile Scurvy
     Lowe's Syndrome
     Osteomalacia
     Pseudovitamin D Deficiency Rickets
     Hypophosphatemic Rickets

General Discussion

** REMINDER **
The Information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.

Vitamin-D Deficiency Rickets is a disorder that appears during infancy
and childhood.  It is caused by insufficient amounts vitamin D in the body.
The vitamin deficiency can be caused by poor nutrition, a lack of exposure to
the sun, or malabsorption syndromes in which the intestines do not adequately
absorb nutrients from foods.  Vitamin D is needed for the metabolism of
calcium and phosphorus in the body which in turn affects how calcium is
deposited in the bones.  Without vitamin D the patients bones are not normal.
Major symptoms of Vitamin-D Deficiency Rickets include bone disease,
restlessness, and slow growth.  This disorder is rare in the United States
but not uncommon in certain areas of the world.

Symptoms

Symptoms of Vitamin-D Deficiency Rickets in infants may be restlessness, lack
of sleep, slow growth, a delay in crawling, sitting or walking, thinness of
the top and back of the skull (craniotabes), swelling of the skull (bossing),
bead-like nodules where the ribs and their cartilages join due to the rapid
growth of the arms and the rib cage (rachitic rosary), and a delay in the
closing of the skull bone.

If Vitamin-D Deficiency Rickets is not treated, the ends of the long
bones may become enlarged, the legs may become bowed and knock-knees may
result.  Muscles can become weak and the chest may become deformed due to the
pull of the diaphragm on the ribs that have been weakened by rickets
(Harrison's groove).  Abnormal development and decay of teeth may also occur.

In more severe, untreated cases of this disorder the bones may become
fragile and fractures may easily occur.  Convulsions, muscle twitching and
sharp bending of the wrist and ankle joints (tetany spasms) may also be
present.  Occasionally, when there is too little calcium in the blood due to
the lack of vitamin D (hypocalcemia), mental retardation may occur.

Causes

Vitamin-D Deficiency Rickets can be caused by a lack of vitamin D in the
diet, a lack of exposure to the sun, or malabsorption syndromes in which
there is an inability of the intestines to adequately absorb nutrients from
foods.

Nursing mothers who have a diet deficient in vitamin D may get rickets
themselves and pass this condition on to the newborn child.

In areas of the world where cultural habits limit exposure to sun, or the
amount of sun in a day or season is limited, Vitamin-D Deficiency Rickets
tends to be more prevalent.

Affected Population

Vitamin-D Deficiency Rickets affects males and females in equal numbers.
Babies of nursing mothers whose diet is deficient in vitamin D can be
affected with this disorder.

Although Vitamin-D Deficiency Rickets is rare in the United States,
children who are dark skinned and living in cloudy northern cities as well as
children on restricted diets due to cultural or religious beliefs are more
likely to develop this disorder.

Rickets is more common in regions of Asia where there is a lack of
daylight and/or low intake of meat due to a vegetarian diet.  Northern Yemen
and Kuwait are also areas where Vitamin-D Deficiency Rickets are prevalent
due to lack of exposure to the sun because of cultural practices.

Related Disorders

Symptoms of the following disorders can be similar to those of Vitamin D
Deficiency Rickets.  Comparisons may be useful for a differential diagnosis:

Fanconi's Syndrome is a rare disorder characterized by kidney dysfunction
and bone abnormalities similar to those of Vitamin D Deficiency Rickets.
Excess amounts of phosphate, amino acids (usually bicarbonate), glucose, and
uric acid are eliminated in the urine.  This disorder is thought to be
inherited through recessive genes.  Bone symptoms include rickets in children
and softening of the bones (osteomalacia) in adults.  Fanconi's Syndrome may
be associated with a variety of inherited metabolic disorders such as
cystinosis, Lowe's Syndrome, a form of Tyrosinemia, hereditary fructose
intolerance, Wilson's Disease, Galactosemia and glycogen storage disorders.
(For more information on this disorder choose "Fanconi" as your search term
in the Rare Disease Database).

Infantile Scurvy is a disease that is caused by a lack of vitamin C in
the diet.  Symptoms of this disorder may be anemia, weakness, sores in the
mouth, loosening of the teeth, irritability, loss of appetite, failure to
gain weight and bleeding under the tissue layer covering the bones.  Scurvy
is treated with large amounts of vitamin C .

Lowe's Syndrome is a rare inherited, metabolic disorder characterized by
eye abnormalities such as congenital cataracts and glaucoma, bone
malformations caused by vitamin D resistant rickets, mental retardation and
impairment of kidney function.  This disorder affects only males and is most
common in those with fair coloring.  Lowe's Syndrome is transmitted through
x-linked recessive genes.  (For more information on this disorder choose
"Lowe" as your search term in the Rare Disease Database).

Osteomalacia is a disorder characterized by a gradual softening and
bending of the bones.  Pain may occur in various degrees of severity.
Softening occurs because solid bones have failed to form properly (calcify)
due to the lack of vitamin D or a kidney dysfunction.  This disorder is more
common in females than males, and often begins during pregnancy.  It can
exist alone or in association with other disorders.

Hypophosphatemic Rickets is a rare genetic form of Rickets characterized
by impaired transport of phosphate and diminished Vitamin-D metabolism in the
kidneys.  Calcium and phosphate are not absorbed properly in the intestines
which can lead to softening of bones.  Major symptoms of this disorder
include skeletal changes, weakness and slow growth.  Cases affecting females
are usually less severe than those affecting males.  One rare acquired form
of this disorder may be associated with a benign tumor.  (For more
information on this disorder choose "Hypophosphatemic Rickets" as your search
term in the Rare Disease Database).

Pseudovitamin D Deficiency Rickets (Vitamin-D Dependent Rickets, Type I)
is characterized by more severe skeletal changes and weakness than those of
Hypophosphatemic Rickets.  This disorder is caused by abnormal vitamin D
metabolism and is inherited as an autosomal recessive trait.  This type of
Rickets often begins earlier than Hypophosphatemic Rickets.  Blood levels of
calcium are severely diminished in patients with Vitamin-D Dependent Rickets.
Amino acids become lost in the urine due to abnormal kidney function.
Intermittent muscle cramps may occur.  Convulsions and abnormalities of the
spine and pelvis may also develop.

Therapies:  Standard

Vitamin-D Deficiency Rickets can be prevented by providing a normal balanced
diet to infants and children, assuming that they are exposed to adequate
amounts of sun.

Treatment of Vitamin D Deficiency Rickets is accomplished with doses of
vitamin D given daily until the bone disease is cured.  The dose of vitamin D
can then be reduced to the daily recommended requirement.

In more severe cases of Vitamin D Deficiency Rickets when cramps,
convulsions, muscle twitching and sharp bending of the ankle and wrist joints
(tetany) is present the treatment with vitamin D is supplemented with calcium
salts intravenously.

Therapies:  Investigational

This disease entry is based upon medical information available through
January 1992.  Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.

Resources

For more information on Vitamin-D Deficiency Rickets, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     National Digestive Diseases Information Clearinghouse
     Box NDDIC
     Bethesda, MD  20892
     [phone]

References

INTERNAL MEDICINE, 2nd Ed.:  Jay H. Stein, Editor-In-Chief; Little, Brown and
Co., 1987.  Pp.  2106-12.

THE MERCK MANUAL, 15TH ED.:  Robert Berkow, Editor-In-Chief; Merck & Co.,
Inc., 1987.  Pp. 924-27.
NUTRITIONAL RICKETS:  K.W. Feldman, et al.; Am Fam Physicians (November,
1990, issue 42(5)).  Pp. 1311-18.

HIGH PREVALENCE OF RICKETS IN INFANTS ON MACROBIOTIC DIETS:  P.C.
Dagnelie, et al.; Am J Clin Nutr (February, 1990, issue 51(2)).  Pp. 202-8.

NUTRITIONAL RICKETS IN SAN DIEGO:  I. Hayward, et al.; Am J Dis Child
(October, 1987, issue 141(10)).  Pp. 1060-2.

VITAMIN D DEFICIENCY RICKETS:  D.M. Kruger, et al,;  Clin Orthop
(November, 1987, issue (224)).  Pp. 277-83.

PHOTOSYNTHESIS OF VITAMIN D IN THE SKIN:  EFFECT OF ENVIRONMENTAL AND
LIFE-STYLE VARIABLES:  M.F. Holick; Fed Proc (April, 1987, issue 46(5)).  Pp.
1876-82.

THE IMPORTANCE OF LIMITED EXPOSURE TO ULTRAVIOLET RADIATION AND DIETARY
FACTORS IN THE ETIOLOGY OF ASIAN RICKETS:  A RISK-FACTOR MODEL:  J.B.
Henderson, et al,; Q J Med (May, 1987, issue 63(241)).  Pp. 413-25.

HIGH LEVELS OF CHILDHOOD RICKETS IN RURAL NORTH YEMEN:  P. Underwood, et
al,; Soc Sci Med (1987, issue 24(1)).  Pp. 37-41.

VITAMIN-D DEFICIENCY RICKETS IN KUWAIT:  THE PREVALENCE OF A PREVENTABLE
DISEASE:  M.M. Lubani, et al,; Ann Trop Paediatr (September, 1989, issue
9(3)).  Pp. 134-9.

OSTEOMALACIA OF THE MOTHER--RICKETS OF THE NEWBORN:  W. Park, et al,; Eur
J Pediatr (May, 1987, issue 146(3)).  Pp. 292-3.