Magnesium and calcium contents in foods from SE Spain: influencing factors and estimation of daily dietary intakes.

The magnesium and calcium content (fresh weight basis) of 243 food, 69 beverages and 11 potable water samples were determined using flame atomic absorption spectrometry. Analyses of NIST and CBR-CEC reference materials demonstrated the reliability and accuracy of this technique. The highest magnesium and calcium levels corresponded to molluscs and crustacea, and dairy products, respectively. Magnesium concentrations found in different food groups were significantly and linearly related with corresponding calcium levels (P<0.001) with the exception of fish products. Significant linear relationships among magnesium and calcium concentrations, and fiber content for cereals, legumes and dry-fruits were found (P<0.001); however, total fat contents of considered foods were not related (P>0.05) with levels of elements considered. Significant linear relationships among magnesium and calcium concentrations in cereals, legumes and fruits, and protein content were found (P<0.001). In meat and by-products, magnesium concentrations found in organ meats were significantly lower (P<0.01); for calcium, levels measured in sausages were significantly higher (P<0.001) than those found in meats and organ meats. In fish products, magnesium levels in molluscs and crustacea were significantly higher than those measured in fish and cephalopoda (P<0.001); for calcium, concentrations in cephalopoda were significantly lower (P<0.001). Mean magnesium and calcium concentrations analyzed in cheese were statistically higher than those determined in other dairy products (P<0.01). In alcoholic drinks, magnesium and calcium levels measured in distilled beverages (whisky, gin, rum, brandy and alcoholic liquors) were statistically lower than those found in fermented types (wine and beer) (P<0.01). The daily intake of magnesium and calcium in the Spanish diet was 366.1 and 1266.6 mg/day per person, respectively. Results revealed that the intake of analyzed elements was similar to recommended dietary allowances.