Evaluation of calcium supplementation with algae (Lithothamnion muelleri) on metabolic and inflammatory parameters in mice fed a high refined carbohydrate-containing diet.

The aim of the present study was to evaluate the potential of calcium supplementation from Lithothamnium muelleri algae on metabolic and inflammatory parameters in mice with increased adiposity. Male mice were fed and divided during 8 weeks in: control (C), a high refined carbohydrate-containing diet (HC), HC diet supplemented with 1% of Lithothamnion muelleri algae (HC + A) and HC diet supplemented with 0.9% calcium carbonate (HC + C). Animals fed HC diet had increased body weight gain and adiposity, serum glucose and cholesterol, glucose intolerance and decreased insulin sensitivity, compared to control diet. However, the HC + A and HC + C groups did not prevent these aspects and were not able to change the CD14 + cells population in adipose tissue of animals fed HC diet. Calcium supplementation with Lithothamnium muelleri algae and calcium carbonate had no protective effect against the development of adiposity, metabolic and inflammatory alterations induced by HC diet.

Effect of shellfish calcium on the apparent absorption of calcium and bone metabolism in ovariectomized rats.

Fossil shellfish powder (FS) and Ezo giant scallop shell powder (EG) were rendered soluble with lactate and citrate under decompression (FSEx and EGEx, respectively) and we examined the effects of lactate-citrate solubilization of FS and EG on mineral absorption, tissue mineral contents, serum biochemical indices and bone mineral density (BMD) in ovariectomized (OVX) rats. The apparent absorption ratios of minerals tended to be high in the rats fed with the solubilized mineral sources, those in the FSEx group being significantly higher than in the FS group. There was no significant difference in the tibia mineral content among the OVX groups. BMD at the distal femoral diaphysis was significantly increased by FSEx and EGEx feeding. It is suggested that solubilization with lactate and citrate under decompression increased the solubility and bioavailability of calcium from such natural sources of shellfish calcium as FS and EG.

Increase of bone mineral density by calcium supplement with oyster shell electrolysate.

The effect of calcium supplementation, in patients with osteoporosis is still a matter of controversy. Oyster shell electrolysate (OSE) was reported to raise serum calcium and increase urinary calcium excretion in vitamin D-deficient states more readily than calcium carbonate. Since the effect of calcium salts on osteoporosis depends heavily on its bioavailability, the effect of 900 mg/day calcium as OSE was tested in 12 elderly osteoporotic females, using radial bone mineral density measured by single photon absorptiometry and spinal trabecular bone density measured by quantitative computed tomography (QCT) as indicated, in comparison with 21 untreated controls in the same geriatric hospital. Radial bone mineral density significantly increased from the pre-test value after 12 and 24 months in subjects given OSE by paired t-test, whereas it fell significantly in the controls. The spinal QCT value on OSE did not change significantly in either the subjects under treatment with OSE, or the controls. Thus OSE may favorably influence osteoporosis by providing a readily available source of calcium.