Abstract
The effects of calcium ion and broad pH ranges on free fluoride ion aqueous concentrations were measured directly and computed theoretically. Solubility calculations indicate that blood fluoride concentrations that occur in lethal poisonings would decrease calcium below prevailing levels. Acute lethal poisoning and also many of the chronic effects of fluoride involve alterations in the chemical activity of calcium by the fluoride ion. Natural calcium fluoride with low solubility and toxicity from ingestion is distinct from fully soluble toxic industrial fluorides. The toxicity of fluoride is determined by environmental conditions and the positive cations present. At a pH typical of gastric juice, fluoride is largely protonated as hydrofluoric acid HF. Industrial fluoride ingested from treated water enters saliva at levels too low to affect dental caries. Blood levels during lifelong consumption can harm heart, bone, brain, and even developing teeth enamel. The widespread policy known as water fluoridation is discussed in light of these findings
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Environmental and physiological factors affecting dental fluorosis
In addition to differences in fluoride intake and possibly to calcium deficiency or malnutrition, there are several factors which may account for individual differences in the occurrence of dental fluorosis. Disorders in acid-base balance affect the renal handling of fluoride such that, in acidosis, the excretion rate is diminished and,
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Effects of plasma fluoride and dietary calcium concentrations on GI absorption and secretion of fluoride in the rat
This 30-day balance study with weanling rats was designed to determine the effects of plasma fluoride and dietary calcium concentration and their interaction on the absorption, balance, and tissue concentrations of fluoride. The three major groups differed according to the total exposure and plasma concentrations of fluoride. One group received
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Fluoride metabolism
Knowledge of all aspects of fluoride metabolism is essential for comprehending the biological effects of this ion in humans as well as to drive the prevention (and treatment) of fluoride toxicity. Several aspects of fluoride metabolism - including gastric absorption, distribution and renal excretion - are pH-dependent because the coefficient
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Modulation of fluoride toxicity in rats by calcium carbonate and by withdrawal of fluoride exposure.
In order to assess the effect of calcium on the toxic effects of fluoride, adult female Wistar rats were treated with sodium fluoride (NaF, 500 ppm in drinking water) alone or in combination with calcium carbonate (CaCO3, 50 mg/kg by oral intubation) daily for 60 days. Food, water and fluoride
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The association of fluoride in drinking water with serum calcium, vitamin D and parathyroid hormone in pregnant women and newborn infants.
Background: Chronic exposure to fluoride in drinking water causes an increase in plasma fluoride levels that is related to a reduction in calcium transport across the renal tubule endoplasmic reticulum and plasma membrane. In the present study, it was hypothesised that varying levels of fluoride present in drinking
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Nutrient Deficiencies Enhance Fluoride Toxicity
It has been known since the 1930s that poor nutrition enhances the toxicity of fluoride. As discussed below, nutrient deficiencies have been specifically linked to increased susceptibility to fluoride-induced tooth damage (dental fluorosis), bone damage (osteomalacia), neurotoxicity (reduced intelligence), and mutagenicity. The nutrients of primary importance appear to be calcium,
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Fluoride Exposure Aggravates the Impact of Iodine Deficiency
A consistent body of animal and human research shows that fluoride exposure worsens the impact of an iodine deficiency. Iodine is the basic building block of the T3 and T4 hormones and thus an adequate iodine intake is essential for the proper functioning of the thyroid gland. When iodine intake is inadequate during infancy and
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Fluoride Exposure Increases Metabolic Requirement for Magnesium
Fluoride's toxicity is significantly enhanced in the presence of nutritional deficiencies. Similarly, fluoride exposure increases the body's requirement for certain nutrients. An individual with a high intake of fluoride, for example, will need a proportional increase in calcium to avoid the mineralization defects (e.g., osteomalacia) that fluoride causes to bone
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Mayo Clinic: Fluoridation & Bone Disease in Renal Patients
The available evidence suggests that some patients wtih long-term renal failure are being affected by drinking water with as little as 2 ppm fluoride. The finding of adverse effects in patients drinking water with 2 ppm of fluoride suggests that a few similar cases may be found in patients imbibing 1 ppm, especially if large volumes are consumed, or in heavy tea drinkers. The finding of adverse effects in patients drinking water with 2 ppm of fluoride suggests that a few similar cases may be found in patients imbibing 1 ppm, especially if large volumes are consumed, or in heavy tea drinkers and if fluoride is indeed the cause. It would seem prudent, therefore, to monitor the fluoride intake of patients with renal failure living in high fluoride areas.
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Dental Fluorosis & Enamel Hypoplasia in Children with Kidney Disease
Children with kidney disease are known to have high levels of fluoride in their blood and to be at risk for disfiguring tooth defects. Research suggests that high levels of fluoride in blood, which can cause the tooth defect known as dental fluorosis, can contribute to the defects that occur
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