Rickets
May 16th, 2008 Posted by: admin
Rickets is the softening and weakening of bones in children, usually because of an extreme and prolonged vitamin D deficiency.
Vitamin D is essential in promoting absorption of calcium and phosphorus from the gastrointestinal tract, which children need to build strong bones. A deficiency of vitamin D makes it difficult to maintain proper calcium and phosphorus levels in your bones.
If the levels of calcium and phosphorus in your bloodstream are low, your body reacts by taking calcium and phosphorus from your bones to raise blood levels to where they need to be. This softens or weakens the bone structure, resulting most commonly in skeletal deformities such as bowlegs or improper curvature of the spine. Osteomalacia is the adult version of rickets.
If a vitamin D or calcium deficiency causes rickets, adding vitamin D or calcium to the diet generally corrects any resulting bone problems for the child. Rickets due to a genetic condition may require additional medications or specialized treatment. Some skeletal deformities caused by rickets may need corrective surgery.
Signs and symptoms
Vitamin D deficiency begins months before physical signs and symptoms of rickets appear. When rickets symptoms develop, they may include:
- Skeletal deformities: bowed legs, abnormal curvature of the spine, pelvic deformities and breastbone projection in the chest.
- Fragile bones. Children with rickets are more prone to bone fractures.
- Impaired growth. Delayed growth in height or limbs may be a result of rickets.
- Dental problems. These include defects in tooth structure, increased chance of cavities, poor enamel and delayed formation of teeth.
- Bone pain. This includes dull, aching pain or tenderness in the spine, pelvis and legs.
- Muscle weakness. Decreased muscle tone may make movement uncomfortable.
Causes
Vitamin D acts as a hormone to regulate calcium and phosphorus levels in your bones. You absorb vitamin D from two sources:
- Sunlight. Skin produces vitamin D when it’s exposed to sunlight. This is the most common way for most adolescents and adults to produce the vitamin.
- Food. Your intestines absorb vitamin D from the foods you eat or from supplements or multivitamins you may take.
In the past, the most common causeof rickets was the dietary vitamin D deficiency. Now, with the increased use of vitamin supplements and the variety of foods fortified with vitamin D (such as orange juice and breakfast cereals), vitamin D deficiency cases of rickets have fallen.
Currently, the cases of rickets are caused by conditions that impair vitamin D absorption such as the surgical removal of all or part of the stomach (gastrectomy) and celiac disease, in which the small intestine doesn’t absorb certain nutrients from food.
Other causes of rickets include: hereditary rickets (X-linked hypophosphatemia), lack of exposure to sunlight
Risk factors
Children 6 to 24 months old are most at risk of rickets because they’re growing rapidly, and vitamin D, calcium and phosphorus play a major role in the growth process.
Risk factors for rickets include:
- Lack of vitamin D. Breast-fed infants who don’t receive supplemental vitamin D are at increased risk of developing rickets.
- Lack of calcium and phosphorus. Children who don’t get enough calcium and phosphorus in their diets are at increased risk of rickets.
Screening and diagnosis
The diagnose of rickets may be done on the basis of:
- Physical examination: check of the source of the pain or tenderness
- Blood tests: level of calcium and phosphorus
- X-rays: images of affected bones to look for softening or weakness
- Medical history: Kidney problems, celiac disease or diagnosis of a sibling with rickets may help lead your doctor to a rickets diagnosis.
Complications
Altghough it can be easily treated once it’s diagnosed, rickets has a severe list of complications if left untreated. Untreated vitamin D deficiency rickets may lead to:
- Delays in your child’s motor skills development
- Failure to grow and develop normally
- Increased susceptibility to serious infections
- Skeletal deformities
- Chronic growth problems that can result in short stature (adults measuring less than 5 feet tall)
- Seizures
- Dental defects
Treatment
The aim of treatment for rickets is to solve the underlying disorder.
If a vitamin D or calcium deficiency causes rickets, adding vitamin D or calcium to the diet generally corrects any resulting bone problems for the child and eliminates the signs and symptoms of rickets (such as bone tenderness ans muscle weakness). Rickets due to a genetic condition may require additional medications or specialized treatment. Some skeletal deformities caused by rickets may need corrective surgery.
Besides taking a vitamin D supplement it is needed to increase the intake of vitamin D-fortified foods. This includes fortified breakfast cereal, orange juice, fish and processed milk. Your doctor may also recommend that you get a little sun. Remember that moderate exposure is the safest, and don’t expose infants under 6 months to direct sunlight.
Getting a sufficient intake of calcium is crucial to maintaining healthy bones The combination of increased vitamin D intake with calcium may be enough to eliminate the effects of rickets entirely.
Treating complications
For some cases of bowlegs or spinal deformities, your doctor may suggest special bracing to position your child’s body appropriately as the bones grow. More severe skeletal deformities may require surgery.
Prevention
Most adolescents and adults receive much of their necessary vitamin D from exposure to sunlight, but in infants and young children the problme is more delicate. They need to avoid direct sun entirely or be especially careful by always wearing sunscreen.
Vitamin D supplements
Considering these factors, and because human milk contains only a small amount of vitamin D, the American Academy of Pediatrics recommends that all breast-fed infants receive 200 international units (IU) of oral vitamin D daily beginning during the first two months of life and continuing until the daily consumption of vitamin D-fortified formula or milk is two to three glasses or 500 milliliters (mL). These suplements must be carefully adminstered, because high concentrations are unsafe for children.
Getting enough calcium
Calcium and phosphorus consumption are also important for bone formation in childhood. Breast milk is the best source of calcium during a child’s first year of life. In adolescents and adults the lack of calcium may lead to osteomalacia, a form of rickets in adults.
Sources of calcium: milk, yogourt, cheese,leafy green vegetables (spinach), fortified orange juices, fortified breakfast cereals and calcium supplements.
Table 1: Adequate Intakes (AIs) for Vitamin D
| Age |
Children |
Men |
Women |
Pregnancy |
Lactation |
| Birth to 13 years | 5 mcg (200 IU) |
||||
| 14-18 years | 5 mcg (200 IU) |
5 mcg (200 IU) |
5 mcg (200 IU) |
5 mcg (200 IU) |
|
| 19-50 years | 5 mcg (200 IU) |
5 mcg (200 IU) |
5 mcg (200 IU) |
5 mcg (200 IU) |
|
| 51-70 years | 10 mcg (400 IU) |
10 mcg (400 IU) |
|||
| 71+ years | 15 mcg (600 IU) |
15 mcg (600 IU) |
Table 2: Selected Food Sources of Vitamin D
| Food |
IUs per serving* |
Percent DV** |
| Cod liver oil, 1 tablespoon |
1,360 |
340 |
| Salmon, cooked, 3.5 ounces |
360 |
90 |
| Mackerel, cooked, 3.5 ounces |
345 |
90 |
| Tuna fish, canned in oil, 3 ounces |
200 |
50 |
| Sardines, canned in oil, drained, 1.75 ounces |
250 |
70 |
| Milk, nonfat, reduced fat, and whole, vitamin D-fortified, 1 cup |
98 |
25 |
| Margarine, fortified, 1 tablespoon |
60 |
15 |
| Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV) |
40 |
10 |
| Egg, 1 whole (vitamin D is found in yolk) |
20 |
6 |
| Liver, beef, cooked, 3.5 ounces |
15 |
4 |
| Cheese, Swiss, 1 ounce |
12 |
4 |
Health Risks from Excessive Vitamin D
The intake of D vitamine should be supervised by a doctor, because the excesive Vitamin D can be damagining to your body. It can cause nonspecific symptoms such as nausea, vomiting, poor appetite, constipation, weakness, and weight loss. Further more, it can also raise blood levels of calcium, causing mental status changes such as confusion and heart rhythm abnormalities. The use of supplements of both calcium (1,000 mg/day) and vitamin D (400 IU/day) by postmenopausal women is considered to possibly be associated with a 17% increase in the risk of kidney stones. Deposition of calcium and phosphate in the kidneys and other soft tissues can also be caused by excessive vitamin D levels .