Calcium bis[2-[(2-hydroxynaphthyl)azo]naphthalenesulphonate]

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: this report is an EFSA-statement on calcium-sulphate in mineral water and includes data from secondary sources

Data source

Reference

Reference Type:

secondary source

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Objective of study:

absorption

Test material

Test material information

Constituent 1

Test animals

Species:

other: rat and human

Administration / exposure

Route of administration:

oral: unspecified

Applicant's summary and conclusion

Executive summary:

ANIMAL DATA ON ABSORPTION OF CALCIUM FROM CALCIUM ENRICHED DIETS

In order to compare bioavailability of calcium from different sources young male rats (7- 10 animals/group) were fed ad libitum on a basal diet to which was added one of a number of calcium sources (carbonate, chloride, hydroxide, sulphate, oxide, lactate, acetate or propionate or yeast) to provide 0.25% calcium with a dietary Ca to P ratio of 1: 2 for 4 consecutive weeks. Calcium seemed to be equally available from all sources based on growth response, efficiency of utilization of diet, apparent absorption of Ca, Ca in serum and Ca in femur (Ranhotra et al., 1980).

HUMAN DATA ON ABSORPTION OF CALCIUM FROM CALCIUM-RICH MINERAL WATERS AND OTHER FOODS The bioavailability of calcium from mineral water containing calcium sulphate was studied in 15 lactose intolerant male individuals and compared to that from milk. In eight of 15 subjects, there was a higher level of calcium absorption from mineral water than from milk. Bioavailability was similar in five of 15 subjects. The bioavailabilty of calcium absorption from milk was greater than that from mineral water in two of 15 subjects (Harpern et al., 1991).

Calcium bioavailability from natural calcium and sulphate rich mineral water was compared with that from milk in nine healthy young women. Calcium absorption was measured in the fasting state with a dual-label stable isotope technique. Fractional absorption rates were 25.0 ± 6.7% (mean ± SD) from milk and 23.8 ± 4.8% (p>0.05) from mineral water. No significant difference was found in the excretion of calcium, or in the excretion of the two stable calcium isotopes. It was concluded that calcium from the calcium- and sulphate-rich mineral water was as well absorbed and retained as that from milk, and no calciuric effect of sulphate was found (Couzy et al., 1995).

No data were available on the bioavailability of calcium sulphate as a mineral substance in foods other than water and water based beverages. However, because absorption of calcium in the intestine requires that it is in a soluble form or bound to soluble organic molecules the bioavailability of calcium sulphate and calcium sulphate dihydrate is not expected to be significantly different from that of calcium chloride and calcium carbonate, respectively. Calcium chloride and calcium carbonate are already permitted as source of calcium in foods for particular nutritional uses and in food supplements.