What is it ?
Osteomalacia is a generalized osteopathy (bone pathology). This condition is the result of primary mineralization deficient in the bone matrix making the bone “soft” and can cause its deformation. In the case of osteomalacia, the bone mass is normal but the mineralization of the osteoid tissue is deficient, consequence of an accumulation of osteoblasts (cells secreting the bone matrix). Osteomalacia is different from osteoporosis, in which bone mass is deficient, but bone mineralization is normal.
The bone matrix is the generic term defining the “organic” substance on which a “mineral” substance is fixed. This mineral substance is characterized by a mixture of calcium and phosphorus. These minerals give the bone its hardness and resistance.
In the case of osteomalacia, this bone matrix is therefore of normal density. The problem results from insufficient fixation of calcium crystals on this bone matrix. Several cases may explain this calcium deficiency:
(1) Calcium fixation is favored by a vitamin D intake. This vitamin comes into play in the absorption and in the metabolism of calcium. A deficient supply of Vitamin D can therefore be the cause of insufficient calcium fixation on the bone matrix.
(2) The regulation of the level of calcium in the blood is regulated, inter alia, by a hormone secreted by the parathyroid glands (located in the neck): parathyroid hormone. An excess of this hormone can also interfere with the fixation of the mineral in the bone matrix.
(3) Daily intakes of calcium through diet vary according to the age and the physiological state of the person:
– Between 4 to 8 years: 800 mg / d
– Between 9 and 18 years: 1,300 mg / d
– Between 19 and 50 years old: 1,000 mg / day
– Between 50 years and over: 1,200 mg / day
– For pregnant and lactating women: 1,000 mg / day
Less calcium intake in relation to daily recommendations can lead to the person a calcium deficiency and thus generate deficient bone mineralization.
the bone becomes more ductile because of this mineral insufficiency in the bone frame. Some bones of the body support larger loads (vertebrae, legs). These may then deform or even crack.
In children, osteomalacia is synonymous with rickets.
Symptoms of Osteomalacia
Symptoms specific to osteomalacia are mainly pain in the bones. These pains can be localized in the legs (accentuated during walking, running, etc.), spine, ribs, shoulder blades, pelvis, and others.
This rheumatism is essentially nonspecific and diffuse enough.
To these pains can be added more or less visible deformities or mechanical characteristics: waddling gait, proximal myopathy (pathology affecting muscle fibers), muscle weakness, etc.
In the case of severe forms, osteomalacia can be characterized by a thorax “bell” or “violin”, a sternum carina or a loss of size.
Calcium is also an essential mineral salt in the formation of teething. In addition to the bone symptoms, abnormalities in the tooth enamel (loss of teeth brightness and embrittlement of the teeth) may occur.
The origins of the disease
Osteomalacia is due to a lack of calcium in the bone structure. Both of these conditions are due to vitamin D and / or calcium deficiency from diet (or exposure to natural sunlight for Vitamin D).
Rickets affects children who are growing and whose bones are still forming.
Osteomalacia affects adults (more women and older people) whose bone mass is well formed.
Risk factors for Osteomalacia
Osteomalacia is a pathology affecting mainly women and the elderly.
Nevertheless, certain factors may be at the origin of an increased risk of the development of this pathology such as taking anticonvulsant drugs, cancers, phosphate, vitamin D, insufficient exposure to the sun, a family history of disorders of the Vitamin D metabolism, kidney failure, some liver diseases, etc.
Children with insufficient vitamin D and calcium intake may also be affected by this type of pathology in the form of rickets.
Prevention and treatment of Osteomalacia
An early diagnosis of this pathology allows limiting the consequences.
After consultation with the doctor, he may prescribe a calcium phosphate test to assess calcium, phosphorus and albumin deficiencies. This assessment can be completed by a calcium dosage in the urine (calciurie).
These controls may be accompanied by x-rays of the painful bones. The presence of a slightly dirty opaque appearance and Looser-Milkman streaks (characteristics of this rheumatism) may be significant for osteomalacia.
In addition, the CT scan of the spine makes it possible to study the structure of the vertebrae.
Finally, it is also possible to perform a bone biopsy to find demineralized bone tissue and increased activity of osteoblasts.
The treatment of osteomalacia is primarily preventive.
A recommended daily intake of calcium prevents any mineral calcium deficiency. This daily intake is through food (mainly in dairy products, fish and fortified soy beverages) but also thanks to some mineral waters rich in calcium and easy to absorb.
Vitamin D is also involved in the prevention of this pathology. We find Vitamin D in the diet (also present in milk, fatty fish such as salmon or trout, eggs, liver, etc.). Vitamin D intake is also possible through moderate exposure to the sun, helping the body to biologically conceive this vitamin.
The curative treatment of the disease consists of a concentrated Vitamin D administration. Usually accompanied by an extra calcium intake.
Increased sun exposure is often recommended for people with osteomalacia.
A well-conducted treatment leads to a rather rapid cure with a decrease or even a disappearance of pain.