Rickets and the Endocrine System - How the Parathyroid Hormone Affects Rickets
Rickets is a deficiency in calcium and phosphate ions that mainly affects children.
This may be largely due to lack of vitamin D or a deficiency of calcium and phosphates in the diet.
Lack of exposure to sunlight may also cause rickets because the active form of vitamin D, which is vitamin D3, requires activation by ultraviolet light.
Without it, vitamin D remains mostly useless and calcium and phosphate absorption remains inadequate.
Children who remain indoors during the winter may also suffer from rickets in the spring.
This is because the liver stores enough vitamin D formed during the summer months and is sufficient to last the child through winter.
Come spring, the stores of vitamin D may run out and rickets can develop.
Parathyroid Hormone in Rickets Because of the decrease in plasma calcium concentration in rickets, the parathyroid glands are stimulated to secrete parathyroid hormone at an increased rate.
While this may help to raise plasma calcium concentrations, phosphate concentrations in the plasma may continue to fall rapidly.
This is due to the action of parathyroid hormones on the kidneys.
While parathyroid hormone prevents the excretion of calcium ions through the kidneys, there is a continuous loss of phosphate ions through the urine still.
It is for this reason that plasma calcium concentrations may only be slightly below normal in the beginning of rickets, while there is a great deficiency in phosphate ions.
In prolonged rickets, however, there is a marked weakness in the bones and bone deformities may eventually occur.
The compensatory increase of parathyroid hormone in response to the low calcium and phosphate ion levels will eventually tap into the bones for more supply.
The bone grows weaker and weaker as parathyroid hormone taps into this calcium-rich source to supply the needs of the body.
While osteoblasts may continue to lay down new layers of bone in growing children, this new bone remains largely uncalcified and is still weaker than normal bone.
Eventually, even the bones will no longer be able to provide for the calcium needs of the body and without treatment, tetany may occur.
Tetany may not set occur in the early stages of rickets because the osteoclasts of the bone can still tap into the bone for the calcium needs of the body.
In prolonged rickets, even the bones may have been depleted of calcium and the body can no longer get the calcium required.
When this happens, a child with rickets may die of tetanic respiratory spasm unless intravenous calcium is administered.
Treatment of Rickets The treatment of rickets relies mainly in supplementing the diet with calcium and phosphates.
Equally important is the addition of vitamin D in the diet to aid in the absorption of calcium and phosphates from the gut.
If little to no vitamin D is administered, there is still minimal absorption of the necessary nutrients and rickets could still occur.
For skeletal deformities, positioning and bracing may help.
Severe deformities may already necessitate surgical correction.
The best treatment for rickets, though, is still prevention.
Make sure you and your children get enough sunlight and enough calcium and vitamin D in your diet.
This may be largely due to lack of vitamin D or a deficiency of calcium and phosphates in the diet.
Lack of exposure to sunlight may also cause rickets because the active form of vitamin D, which is vitamin D3, requires activation by ultraviolet light.
Without it, vitamin D remains mostly useless and calcium and phosphate absorption remains inadequate.
Children who remain indoors during the winter may also suffer from rickets in the spring.
This is because the liver stores enough vitamin D formed during the summer months and is sufficient to last the child through winter.
Come spring, the stores of vitamin D may run out and rickets can develop.
Parathyroid Hormone in Rickets Because of the decrease in plasma calcium concentration in rickets, the parathyroid glands are stimulated to secrete parathyroid hormone at an increased rate.
While this may help to raise plasma calcium concentrations, phosphate concentrations in the plasma may continue to fall rapidly.
This is due to the action of parathyroid hormones on the kidneys.
While parathyroid hormone prevents the excretion of calcium ions through the kidneys, there is a continuous loss of phosphate ions through the urine still.
It is for this reason that plasma calcium concentrations may only be slightly below normal in the beginning of rickets, while there is a great deficiency in phosphate ions.
In prolonged rickets, however, there is a marked weakness in the bones and bone deformities may eventually occur.
The compensatory increase of parathyroid hormone in response to the low calcium and phosphate ion levels will eventually tap into the bones for more supply.
The bone grows weaker and weaker as parathyroid hormone taps into this calcium-rich source to supply the needs of the body.
While osteoblasts may continue to lay down new layers of bone in growing children, this new bone remains largely uncalcified and is still weaker than normal bone.
Eventually, even the bones will no longer be able to provide for the calcium needs of the body and without treatment, tetany may occur.
Tetany may not set occur in the early stages of rickets because the osteoclasts of the bone can still tap into the bone for the calcium needs of the body.
In prolonged rickets, even the bones may have been depleted of calcium and the body can no longer get the calcium required.
When this happens, a child with rickets may die of tetanic respiratory spasm unless intravenous calcium is administered.
Treatment of Rickets The treatment of rickets relies mainly in supplementing the diet with calcium and phosphates.
Equally important is the addition of vitamin D in the diet to aid in the absorption of calcium and phosphates from the gut.
If little to no vitamin D is administered, there is still minimal absorption of the necessary nutrients and rickets could still occur.
For skeletal deformities, positioning and bracing may help.
Severe deformities may already necessitate surgical correction.
The best treatment for rickets, though, is still prevention.
Make sure you and your children get enough sunlight and enough calcium and vitamin D in your diet.