Category Archives: Xylitol

Xylitol Improves Bioavailability of Calcium in Rats

Abstract

Bone repair in calcium-deficient rats: comparison of xylitol+calcium carbonate with calcium carbonate, calcium lactate and calcium citrate on the repletion of calcium.

The potential value of xylitol in calcium therapy was evaluated by comparing the effect of dietary xylitol (50 g/kg diet) + calcium carbonate with the effects of calcium carbonate, calcium lactate and calcium citrate on bone repair of young male rats after the rats consumed for 3 wk a calcium-deficient diet (0.2 g Ca/kg diet). After this calcium-depletion period, the rats were fed for 2 wk one of four diets, each containing 5 g Ca/kg diet as one of the four dietary calcium sources. The diet of the control animals was supplemented with CaCO3 (5 g Ca/kg diet) throughout the study. The Ca-deficient rats showed low bone mass, low serum calcium and high serum 1,25-dihydroxycholecalciferol, parathyroid hormone (1-34 fraction) and osteocalcin concentrations. They also excreted magnesium, phosphate and hydroxyproline in the urine in high concentrations, and had high bone alkaline phosphatase and tartrate-resistant acid phosphatase activities. Most of these changes were reversed by the administered of the calcium salts. The highest recoveries of femoral dry weight, calcium, magnesium and phosphate were observed in the groups receiving xylitol+CaCO3 and calcium lactate. Calcium lactate and calcium citrate caused low serum phosphate concentration compared with rats receiving CaCO3 and with the age-matched Ca-replete controls. Xylitol-treated rats excreted more calcium and magnesium in urine than did the other rats, probably due to increased absorption of these minerals from the gut. These results suggest that dietary xylitol improves the bioavailability of calcium salts.

Hämäläinen MM
J. Nutr. Jun 1994
PMID: 8207545 | Free Full Text

Xylitol Protective Against Bone Loss in Rats

Abstract

Dietary xylitol prevents ovariectomy induced changes of bone inorganic fraction in rats.

Thirty-six 3-month-old female Wistar rats were labelled with a single intraperitoneal tetracycline injection. Twenty-four animals were subsequently ovariectomized, while the control group of 12 animals underwent sham operations. All animals received the basal Ewos R3 diet and half of the ovariectomized animals (n = 12) were given an additional 5% dietary xylitol supplementation. Three months later, following the collection of blood and urine, the animals were killed by decapitation. The tibiae were detached and prepared for chemical and other studies. The weight and density of the tibiae were measured. The right tibiae were dried and pulverized for chemical analysis of calcium, phosphorus and citric acid. The total inorganic fraction was determined by ashing the powdered bone. The left tibiae were cross-sectioned at the tibio-fibular junctions for the measurement of the width of periosteally formed bone, which was identified by tetracycline fluorescence. The examination of mineral content of bone was performed by scanning electron microscopy, using an electron probe microanalytic technique. The results indicate that the supplementation of the diet with 5% xylitol had a protective effect against the loss of bone mineral after ovariectomy in the rat. This was clearly seen in tibial density and in the inorganic fraction of the bone, and in the concentrations of bone Ca and phosphorus. Ovariectomy caused a doubling in periosteal bone formation relative to the controls, whereas the growth of the periosteally formed bone was somewhat reduced following xylitol supplementation as compared with ovariectomy alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Svanberg M, Knuuttila M
Bone Miner Jul 1994
PMID: 7950507

Xylitol Reduces Bone Resorption in Rats

Abstract

Diminished bone resorption in rats after oral xylitol administration: a dose-response study.

The effects of 5, 10, and 20% dietary xylitol supplementations on the resorption of bone were studied. The resorption was measured by the urinary excretion of [3H] radioactivity from [3H]tetracycline-prelabeled rats. The 10 and 20% oral xylitol administrations caused a significant decrease in the excretion of [3H] as compared with the control group with no xylitol supplementation. The effect was detected as early as 2 days after the beginning of xylitol-feeding and was maintained throughout the experimental period of 31 days. The retarding effect on bone resorption was about 25% in the 10% xylitol group, about 40% in the 20% xylitol group, and undetectable in the 5% xylitol group. The amount of preserved [3H] radioactivity in the tibiae of the 10 and 20% xylitol groups after the experiment clearly exceeded the values of the control group. The mechanism of the retarded bone resorption caused by dietary xylitol still remains obscure, but an increased absorption of calcium may be involved. In conclusion, dietary xylitol supplementation in rats seems to retard the bone resorption in a dose-dependent way. The effect is achieved rapidly and is maintained at least over a period of 1 month xylitol feeding.

Mattila P, Svanberg M, Knuuttila M
Calcif. Tissue Int. Mar 1995
PMID: 7750030

Xylitol Improves Recalcification in Rats

Abstract

Comparison of the effect of gluconate, lactose, and xylitol on bone recalcification in calcium-deficient rats.

The therapeutic value of three calcium absorption promoting carbohydrates, lactose, gluconate and xylitol, in bone calcification was evaluated in 7-week-old male rats which were fed on a semisynthetic Ca-deficient diet for 3 weeks. Lactose + CaCO3, xylitol + CaCO3, Ca-gluconate, or CaCO3 alone were administered to the Ca-deficient rats for 2 weeks; the carbohydrate and Ca contents of the diets were 5% and 0.5%, respectively. The Ca-deficient rats showed a decrease in serum total Ca and ionized Ca2+ and in tibial Ca, Mg, P and density, with a concomitant increase in bone hydroxyproline concentration. Bone and serum tartrate-resistant acid phosphatase activities were increased 2-fold and the serum 1,25(OH)2D3 level 5-fold. Smaller increases were found in serum calcitonin, PTH, alkaline phosphatase and osteocalcin levels. These changes (except calcitonin) were reversed by the administration of Ca and the carbohydrates. It was observed that all three agents improved the recalcification of bones compared with the effect of CaCO3 alone. The effect of lactose and xylitol was superior to that of gluconate. These results suggest advantages in the use of xylitol in Ca-supplements.

Hämäläinen MM, Knuuttila M, Svanberg M, Koskinen T
Bone 1990
PMID: 2078437