Paleolithic diets are expected to be beneficial for calcium balance for
1 Calcium INTAKE from vegetables is high. This is because vegetables
are rich in calcium when this is measured in mg per unit of energy,
actually close to dairy products, and because much of the western foods are
low in calcium (e.g. margarine, oil, sugar and cereals).
2 Calcium BIOAVAILABILITY is high when cereals, maize and beans are
absent. These are rich in phytic acid which strongly binds to calcium (and
iron, zinc and magnesium) so that this is excreted without being absorbed
(Sandstead HH. Fiber, phytates, and mineral nutrition. Nutr Rev 1992; 50:
3 Calcium LOSSES are apparently less when salt intake is low. A high
sodium intake increases urinary losses of calcium (Evans C, Eastell R.
Adaptation to high dietary sodium intake. In: Burckhardt P, Heaney RP, ed.
Nutritional aspects of osteoporosis '94. Rome: Ares-Serono Symposia, 1995:
413-8. vol 7; Shortt C, Flynn A. Sodium-calcium inter-relationships with
specific reference to osteoporosis. Nutr Res Rev 1990; 3: 101-15; Schaafsma
G, van BE, Raymakers JA, Duursma SA. Nutritional aspects of osteoporosis.
World Rev Nutr Diet 1987; 49: 121-59) and one study suggests that this may
increase the risk of osteoporosis (Devine A, Criddle RA, Dick IM, Kerr DA,
Prince RL. A longitudinal study of the effect of sodium and calcium intakes
on regional bone density in postmenopausal women. Am J Clin Nutr 1995; 62:
Several studies suggest that bioavailability and urinary losses of calcium
are more important than intake (Nordin BEC, Need AG, Morris HA, Horowitz M,
Chatterton BE, Sedgwick AW. Bad habits and bad bones. In: Burckhardt P,
Heaney RP, ed. Nutritional aspects of osteoporosis '94. Rome: Ares-Serono
Symposia, 1995: 1-25. vol 7).
A no-salt no-cereal diet rich in saturating vegetables would thus seem to