Calcium (Mineral Supplement)
Calcium is the most abundant mineral in the body. Its many functions include building and maintaining strong bones and teeth, blood clotting, transmission of nerve signals, muscle contraction, enzyme activation, hormone release, and maintaining a normal heartbeat.
Natural sources of calcium include dairy products, sardines and salmon, tofu, broccoli and kale, nuts and seeds, and blackstrap molasses. Hard water also makes a significant contribution to calcium intake. Most individuals should be able to obtain sufficient calcium for their needs from a varied, balanced diet.
Phytic acid, found in wheat bran and legumes, and oxalic acid, found in spinach and rhubarb, can bind to calcium and prevent it from being absorbed effectively.
|Daily Recommended Dietary Allowances (RDAs) for Calcium|
|0–6 months||200 mg||200 mg|
|7–12 months||260 mg||260 mg|
|1–3 years||700 mg||700 mg|
|4–8 years||1000 mg||1000 mg|
|9–13 years||1300 mg||1300 mg|
|14–18 years||1300 mg||1300 mg||1300 mg||1300 mg|
|19–50 years||1000 mg||1000 mg||1000 mg||1000 mg|
|51–70 years||1000 mg||1200 mg|
|71+ years||1200 mg||1200 mg|
Committee to Review Dietary Reference Intakes for Vitamin D and Calcium, Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.
The body requires adequate Vitamin D to absorb calcium from the intestines effectively. Too much or too little Vitamin D will therefore affect calcium levels too.
Signs of calcium deficiency include brittle nails, muscle cramps, pins and needles and aching joints, low mood, tooth decay, palpitations, high blood pressure and even high cholesterol. If the amount of calcium absorbed from the diet over a long period is insufficient to meet the body’s needs, there will be a reduction in bone mass leading to osteopenia and osteoporosis and an increased likelihood of fractures. Inadequate amounts of calcium, vitamin D, or phosphates can lead to osteomalacia – softening of the bones.
Calcium deficiency is more common in menopausal and post-menopausal women because a reduction in oestrogen causes a loss of bone mass, increasing the likelihood of fractures and osteoporosis. Calcium supplements are often used in the prevention of osteoporosis.
Recent research has shown that supplementation may also help prevent the development of colorectal cancer in susceptible people.
Chronic kidney disease can prevent the normal absorption of calcium and causes it to be lost in the urine. Pancreatitis, coeliac disease, and inflammatory bowel disease can also prevent proper absorption of calcium.
Hypercalcaemia, or too much calcium, is rare, but may be caused by over-supplementation, thiazide diuretics, or an overactive thyroid gland. It can cause kidney stones, excessive thirst and urination, and weakened bones and muscles.
Calcium may interfere with the absorption of some drugs including blood pressure medication, digoxin and antibiotics. Long-term use of corticosteroids and anti-seizure medication may lead to calcium deficiency.
NB You should always seek professional advice before taking mineral supplements.