Calcium is required in development and maintenance of the skeleton as well as for the proper functioning of neuromuscular and cardiac function. It is stored in the teeth and bones where it provides structure and strength.
Low intakes of calcium can cause low bone density conditions such as osteoporosis and is one of the major causes of morbidity amongst older Australians and New Zealanders, particularly postmenopausal women. Calcium intake throughout life is a major factor however other factors, notably adequate vitamin D status and exercise, also play a role.
Bone mass increases by about sevenfold from birth to puberty and a further threefold during adolescence and then remains stable until about age 50 in men and until the menopause in women. During the adolescent growth spurt, the required calcium retention is two to three times higher than that required for the development of peak bone mass which occurs at the same time as maximum height.
For approximately 5-10 years both during and after the climacteric and menopause, women lose bone more rapidly than men (2%-3% per year). Thereafter, the age-related loss in both sexes is about 0.5 to 1.0% per annum. All of the body’s calcium reserve is stored in the skeleton. The size of the reserve is directly affected by the body’s external calcium balance which depends on the relation between calcium intake and absorption on the one hand and losses of calcium through the skin, kidney and bowel on the other.
Calcium is found predominantly in dairy foods, bony fish, legumes and certain nuts. Consumption of vegan diets may influence calcium needs because of their relatively high oxalate and phytate content, however, vegans can attain calcium balance and studies show to have similar calcium intakes to omnivores, and similar urinary excretion.
Intakes of calcium in adults in Australia and New Zealand average about 850 mg of which about 40% comes from non-dairy sources.
For natural food sources of calcium, content is of equal or greater importance than bioavailability. The efficiency of calcium absorption varies across foods as calcium may be poorly absorbed from foods rich in oxalic acid as these inhibit some absorption (eg spinach, rhubarb, beans) or phytic acid (seeds, nuts, grains, certain raw beans and soy isolates). Compared to milk, calcium absorption from dried beans is about 50% and from spinach 10%.
*Tip – Soaking your legumes, nuts and seeds (including Quinoa) for a minimum of 12hrs up to 24hrs then rinsing thoroughly helps to remove the Phytic acid helping make them more digestible and the nutrients more bioavailable.
Most people think of calcium as being found typically only in dairy, however calcium is found in a range of foods.
1 cup of coconut milk = 38.4
1 tbsp raw cacao = 24gm
1 tbsp Tahini unhulled (sesame seed paste) = 63.9gm
Spinach 1 cup = 29.7
Broccoli 1 cup = 42.8
Kale 1 cup = 105mg
Rocket 1 cup = 20mg
Almonds 30gm = 75gm
Quinoa 1 cup = 31mg
White beans 1 cup = 191gmBlack eyed beans ½ cup = 185mg
Chick peas ½ cup = 100mg
Borlotti beans ½ cup = 127mg
Pinto beans ½ cup = 113mg
Bok choy 1 cup = 70mg
Orange 1 = 65mg
Lemon ¼ = 5mg
Banana medium = 5mg
Strawberries ½ cup = 16mg
Carrots ½ cup = 33mg
Oats 1cup = 187mg
1 tbls Chia seeds = 179mg
1 tbsp. Sunflower seeds = 25mg
1tbsp blackstrap molasses = 200mg
| Gender | EAR | RDI |
| All | ||
| 1-3 yr | 360 mg/day | 500 mg/day |
| 4-8 yr | 520 mg/day | 700 mg/day |
| Boys | ||
| 9-11 yr | 800 mg/day | 1,000 mg/day |
| 12-13 yr | 1,050 mg/day | 1,300 mg/day |
| 14-18 yr | 1,050 mg/day | 1,300 mg/day |
| Girls | ||
| 9-11 yr | 800 mg/day | 1,000 mg/day |
| 12-13 yr | 1,050 mg/day | 1,300 mg/day |
| 14-18 yr | 1,050 mg/day | 1,300 mg/day |
| Age | EAR | RDI |
| Men | ||
| 19-30 yr | 840 mg/day | 1,000 mg/day |
| 31-50 yr | 840 mg/day | 1,000 mg/day |
| 51-70 yr | 840 mg/day | 1,000 mg/day |
| >70 yr | 1,100 mg/day | 1,300 mg/day |
| Women | ||
| 19-30 yr | 840 mg/day | 1,000 mg/day |
| 31-50 yr | 840 mg/day | 1,000 mg/day |
| 51-70 yr | 1,100 mg/day | 1,300 mg/day |
| >70 yr | 1,100 mg/day | 1,300 mg/day |
Reference: https://www.nrv.gov.au/nutrients/calcium