Fluorides are an element from the group of halogens, which occurs as a trace element in the body. It is stored primarily in the bone or in the tooth enamel. There it ensures the strength of the bone or tooth. The absorption rate for oral intake is around 90%. Excretion is exclusively renal (via the kidney). Fluorides are used in the treatment of osteoporosis. Fluorides stimulate osteoblast activity (bone-building cells), which in turn causes calcium to be incorporated into the bones. Fluoride is also used as a caries prophylaxis and in infants to prevent rickets.
The daily requirement is 0.25-0.35 mg. Fluorides are mainly found in black and green tea, but also in sea fish and asparagus.
When fluorides are overdosed, a distinction is made between acute and chronic poisoning.
In acute fluoride poisoning, the following symptoms may occur:
- Gastroenterocolitis – inflammation of the gastrointestinal tract.
- Alveolitis after leather spray!
- Cramps
- Visual disturbances
Chronic fluoride poisoning (fluorosis) may cause the following symptoms:
- Alopecia (hair loss)
- Osteomalacia (softening of the bones)
- Osteoporosis
- Osteosclerosis – increase in bone hardness; this also causes a decrease in the load-bearing capacity of the bone.
The procedure
Material needed
- Blood serum
- Urine
Preparation of the patient
- Not necessary
Disruptive factors
- Not known
Standard values
| Blood serum | 0.2-0.9 mg/l |
| Urine | <30 ng/mlTherapeutic: 80-200 ng/ml |
Biological occupational tolerance level (BAT): 7 mg/g creatinine.
Indications
- Suspicion of fluoride poisoning
- Osteoporosis therapy (determination of fluoride is required 4 months after initiation of therapy; further checks at 4-month intervals thereafter).
Interpretation
Interpretation of lowered values
- Not relevant to disease
Interpretation of elevated values
- Occupational exposure (recognition as occupational disease!).
- Absorption of wood preservatives, insecticides.
- Overdose in therapy