CALCIUM

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Why do I need 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.

What are some of the signs of calcium deficiency?

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

How much do I need?

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, one of the best sources of calcium are sea vegetables, 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.

What are the lifestyle factors that will deplete my calcium stores?

  • Dairy products. Contrary to popular opinion, milk and other dairy products are NOT a good source of calcium. The ratio of phosphorus to calcium is unfavourable and stops the calcium from being absorbed. In fact, regular consumption of dairy products will leach the calcium from your body. Studies have shown that osteoporosis is actually more common in milk drinkers. There are lots of other reasons not to drink your milk that the Dairy Boards won't tell you about.
  • Drinks high in phosphorus (eg. milk, coke, any type of fizzy)
  • Coffee or tea
  • Alcohol
  • Sugar and other refined carbohydrates
  • Processed foods
  • High intakes of protein
  • Synthetic Vit D
  • Mineral oils in cosmetics
  • Prescription drugs including : anticortisone, thyroid meds, aspirin
  • Smoking
  • Lack of exercise. 1% of bone mass is lost per day of being bed-ridden. Specifically,  weight bearing or resistance exercise is needed to build bone mass.
  • Ironically, heavy exercise also increases demands for calcium.
  • It is also suspected that phytic acid in grains & oxalic acid in spinach & parsley bind to calcium and make it unusable. But if you otherwise react well to these foods, eating them in moderation shouldn't be a problem.

But if I can't drink milk, how will I get my calcium?

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
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

I still want to take a calcium supplement. Which forms are best?

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.