DietNet - Calcium

Most people know that calcium is needed for strong, healthy bones and teeth. Women, especially post-menopausal, are in danger of developing osteoporosis if their intake is not sufficient. It is also necessary for correct muscle and nerve action, it helps maintain blood acidity and assists in blood clotting, and maintains healthy skin.

Shrinkage of skeleton, osteoporosis, muscle cramps, tingling or trembling, eye cataracts, slow blood clotting, irregular heart beat, irritability, insomnia and mental disorders.

It depends. If you are subject to some of the lifestyle factors that deplete calcium stores, you will need more.

For example, Dr Watson found that one of the metabolic types (Hunter-Gatherer) needed extra calcium supplementation. This could be because Hunter-Gatherers need a relatively high amount of protein, and a high protein intake inhibits calcium absorption. Luckily, amingst the best sources of calcium are sea vegetables and bone broths, which are very suitable for the Hunter-Gatherer metabolism.

The NZ RDA is 800mg, the US RDA is 1200mg, and Michael Colgan recommends supplementing with up to 1600mg daily.

Relax, there are lots of foods that have calcium in them. And in a more accessible form. The exact amount of each mineral in each food may vary from location to location depending on the conditions, but these figures will give you an indication of what foods are most calcium rich.

Food	Serving size	mg of Calcium
Bone broths:
Amount depends upon how it's made, homemade is best. Click here for good recipes.

Fish :
Salmon, canned, with bones	1 cup	431 mg
Sardines, canned, with bones	100gms (3.6oz)	300mg
Tuna, canned, with bones	100gms (3.6oz)	290mg
Oysters, raw	1 cup	226mg
Fish, fresh, cooked	100gms (3.6oz)	35mg

Nuts and seeds :
Almonds, hulled	1 cup	300mg
Brazil Nuts	1 cup	260mg
Sunflower seeds, hulled	1 cup	174mg
Sesame seeds, ground, unhulled	1 tablespoon	100mg
Tahini (hulled sesame paste)	1 tablespoon	85mg

Soy Products :
Tempeh	112gms (4 oz)	172mg
Tofu	112gms (4 oz)	80-150mg
Soy milk (unfortified)	1 cup	60mg
Soy milk (fortified)	1 cup	300mg

Other Legumes :
Chickpeas, cooked	1 cup	150mg
Black beans, cooked	1 cup	135mg
Baked beans	1 cup	100mg
Corn tortillas	2	120mg

Sea vegetables :
Hijiki	1 cup	610mg
Dulse (dry)	1 cup	567mg
Wakame	1 cup	520mg
Agar-agar	1 cup	400mg
Kelp (kombu)	1 cup	305mg

Vegetables :
Rhubarb, cooked	1 cup	348mg
Collard greens, cooked	1 cup	300mg
Bok choy, cooked	1 cup	200mg
Silver beet or Spinach, cooked	1 cup	180mg
Beet greens, cooked	1 cup	165mg
Broccoli, cooked	1 cup	160mg
Dandelion greens, cooked	1 cup	147mg
Parsley, raw	1 cup	122mg
Watercress, raw	1 cup	53mg

Other :
Black strap molasses	1 tablespoon	137mg
Whey milk	1 cup	175mg
Eggs	2	56mg
Egg yolks	2	52mg

Not all forms of calcium have the same amount of elemental calcium in them, and they also have different absorption rates. Calcium carbonate is the best source, followed by calcium citrate. Read labels carefully to distinguish between 500mg OF calcium carbonate and 500mg elemental calcium FROM calcium carbonate.

Remember that minerals work synergistically. You may need extra magnesium, silicon, fluoride, zinc, copper, boron, manganese, phosphorus and Vitamin D to allow your body to use that extra calcium. If you obtain your calcium from food sources, those extra nutrients are most likely already there.