Calcium metabolism effect

No effect on calcium metabolism in women consuming 800 mg calcium/ d. 

Reported that only coffee among caffeine sources was the significant predictor of hip fracture, although no association between caffeine intake and forearm fracture found. No association between bone density and caffeine intake, although caffeine was found to have significant negative effect on calcium metabolism. 

Smith, S., Swain, J., Brown, E. M., Wyshak, G., Albright, T., Ravnikar, V. A., Schiff, I., A preliminary report of the short-term effect of carbonated beverage consumption on calcium metabolism in normal women, Archives of Internal Medicine, 149, 2517, 1989. 

Four small parathyroid glands are embedded on the posterior surface of the thyroid gland as it wraps around the trachea. Parathyroid hormone (PTH, parathormone) is the principal regulator of calcium metabolism. Its overall effects include ... 

In addition to the well-known iron effects on peroxidative processes, there are also other mechanisms of iron-initiated free radical damage, one of them, the effect of iron ions on calcium metabolism. It has been shown that an increase in free cytosolic calcium may affect cellular redox balance. Stoyanovsky and Cederbaum [174] showed that in the presence of NADPH or ascorbic acid iron ions induced calcium release from liver microsomes. Calcium release occurred only under aerobic conditions and was inhibited by antioxidants Trolox C, glutathione, and ascorbate. It was suggested that the activation of calcium releasing channels by the redox cycling of iron ions may be an important factor in the stimulation of various hepatic disorders in humans with iron overload. 

In attempting to reconcile these findings, it should be pointed out that rats may not be appropriate models for the study of calcium metabolism in humans. Unlike humans, the rat does not undergo epiphyseal plate closure and does not have a significant haversian remodeling sequence (21) Furthermore, rats excrete only l-270 of their calcium intake in their urine whereas humans excrete approximately 20-30% or more. This fact is especially significant, since most of the known effects of phosphates on calcium retention in humans are effected by alterations in urinary calcium. 

Several comprehensive reviews on oxalic acid have been published in which effects on calcium metabolism were discussed (7-11). A review of studies on the effect of oxalic acid on calcium bioavailability in rats and humans is presented in this paper. 

Effect of Dietary Protein, Calcium, and Phosphorus on Calcium Metabolism in Humans... 

These studies have shown that phosphorus, magnesium and fluoride In the doses used had no effect on the bloavailablllty of calcium, while large doses of zinc given during a low calcium Intake Inhibited the Intestinal absorption of calcium The effect of protein and of certain drugs on calcium metabolism Is also described ... 

In extensive studies of the effect of fluoride In patients with osteoporosis carried out In this Research Unit, a therapeutic dally dose of 45 mg fluoride per day was used as sodium fluoride. The main effect of fluoride on calcium metabolism was a decrease of the urinary calcium, while the fecal calcium did not change and the calcium balance also remained unchanged. Also, the Intestinal absorption of calcium remained unchanged during the high fluoride Intake (Table I), The decrease In urinary calcium, Induced by sodium fluoride, may be due to decreased bone resorption, a very desirable effect for patients with osteoporosis. 

Zinc, A great deal of Information Is available on the effect of calcium on zinc metabolism, particularly In animals (30,31), but only a few studies have been carried out In man (32,33), On the other hand, to our knowledge, no studies have been reported on the effect of zinc on calcium metabolism In man. In studies carried out In this Research Unit, It has been demonstrated that large amounts of zinc significantly decrease the Intestinal absorption of calcium If the zinc supplements are given during a low calcium Intake (34),... 

Table III. Effect of Small and Large Doses of Aluminum-Containing Antacids on Calcium Metabolism...

The only study located in animals regarding metabolic effects reported decreased serum albumin and lowered calcium and potassium levels in dogs fed 1.04 mg CNVkg/day as cassava or sodium cyanide for 14 weeks (Kamalu 1993)... 

Carnosine is an avid chelator of metal ions (Baran, 2000). Complexes with calcium, copper, and zinc ions have been described (Trombley et ah, 2000). It is possible, therefore, that carnosine could exert some sort of control of calcium metabolism in muscle tissue (heart or skeletal). It is also likely that the dipeptide controls the availability of zinc ions in neuronal tissue, especially the olfactory lobe where both carnosine and zinc are enriched (Bakardjiev, 1997 Bonfanti et ah, 1999 Sassoe-Pognetto et ah, 1993). Zinc-camosine complexes, called polaprezinc, are also effective in the repair of ulcers and other lesions in the alimentary tract (Matsukura and Tanaka, 2000). 

Chronic exposure can result in obstructive lung disease, emphysema, and kidney disease. Cadmium may also be related to increases in blood pressure (hypertension) and is a possible lung carcinogen. Cadmium affects calcium metabolism and can result in bone loss. This condition has been referred to as Itai-Itai disease, which means Ouch-Ouch in Japanese and reflects the bone pain associated with cadmium effects on calcium. 

The mechanisms by which 2-PAM exerts its cardiac effects have been studied in experimental animals. At least three classes of action have been attributed to the effects of altered calcium metabolism on autonomic ganglia. A sympathomimetic action of 2-PAM was postulated to explain the increase in blood pressure and the augmented myocardial contractility by one or more of the following mechanisms 2-PAM may not block the release of the endogenous compounds, but may prevent the uptake of catecholamine 1 it may stimulate the release of norepinephrine it Increases myocardial contractility by directly stimulating beta receptors and it increases blood pressure by directly stimulating alpha receptors. 5... 

Qin, X. and H. Klandorf. 1991. Effect of dietary boron supplementation on egg production, shell quality, and calcium metabolism in aged breeder hens. Poultry Sci. 70 2131-2138. 

Lactose appears to stimulate the intestinal absorption and retention of calcium. The effect may not be due to lactose but rather to its metabolic product, lactic acid, formed by microbial action in the gut. The... 

Male Hormones. The androgenic hormones produced in Ihe testes land adrenal gland t have a w idespread effect upon the development of secondary sexual characteristics (musculature, facial hair, larynx, etc. I. as well as upon the sexual organs and responses themselves. They also promote anabolism tu a marked degree by their effect upon nitrogen and calcium metabolism. The structure of testosterone is shown in the Tahle I. 

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