In response to a petition submitted by the UK Health Food Manufacturers’ Association (HFMA), the European Food Safety Authority said there were no concerns about the nutrient’s use in food supplements to an upper intake level of 2500mg per day that had been established in 2004 by its predecessor, the SCF.
EFSA’s Scientific Panel on Food Additives and Nutrient Sources added to Food (ANS) found calcium sulphate functions in a manner comparable with other calcium forms and therefore saw no reason to issue any precautionary safety advice.
“On the basis of available studies the ANS Panel considers that the bioavailability of calcium from calcium sulphate is comparable to other inorganic calcium salts and that the use of calcium sulphate as a source of calcium in food supplements is of no safety concern assuming the total dietary exposure to calcium remains within the defined tolerable upper intake level,” the ANS stated.
It added the calcium sulphate must comply with specifications laid down in Directive 2000/63/EC (specific purity of food additives other than colours and sweeteners).
Calcium sulphate (gypsum, CaSO4) exists in an anhydrous form as well as a dihydrate and is permitted as a food additive in most foods “with no other restriction other than good manufacturing practice”.
The HFMA petition noted calcium sulphate daily doses were unlikely to exceed 800mg of calcium (equivalent to 2.7 g calcium sulphate/day), which is the Recommended Daily Allowance defined in Directive 90/496/EEC on nutritional labelling.
Calcium sulphate’s intended use is as a calcium alternative, but the ANS panel said its opinion did not extend to calcium itself, only the sulphate version, although safety questions were raised about other calcium forms.
A Food and Agriculture Organization//World Health Organization Joint Expert Committee on Food Additives (JECFA) had found that calcium sulphate was safe when used a food additive and the body had determined an recommended daily intake (RDI) of 2500mg that did not specify between various calcium forms.
A rat study found no difference in calcium bioavailability from different sources.Human studies showed calcium sulphate bioavailability from mineral waters is comparable to milk and that sulphate anion does not affect the urinary excretion of calcium.
The ANS stated: “If calcium sulphate as a ‘worst case’ scenario would be assumed to be consumed up to the tolerable upper intake level of 2500mg calcium per day this would correspond to an intake of 8.5g calcium sulphate (anhydrous) per day. This would amount to a daily intake of 6g sulphate ion. JECFA states that the few available studies in experimental animals do not raise concern about the toxicity of the sulphate ion in sodium sulphate.”
Another EFSA panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC) found in July no grounds for concern over Magnesium L-lysinate, calcium L-lysinate, zinc L-lysinate as sources for magnesium, calcium and zinc.