Our bodies require more calcium than any other mineral. Our bones contain 98% of our calcium stores, our teeth 1% and the remaining 1% is a vital element to support the normal function of blood clotting, neurotransmission, digestive enzyme activity, insulin secretion, as well as normal heart function and muscle contraction. It is an essential ‘macro-mineral’ and a critical nutrient during pre-conception, pregnancy and breastfeeding.
Muscle spasms and cramping, eyelid twitching, menstrual cramps, backaches, migraines, constipation, poor sleep, skin, nail and hair health and heart flutters may all be symptomatic of an imbalanced calcium to magnesium ratio. Bone health is the number one issue that most people think of when considering a calcium deficiency. Post-menopausal women and elderly people are more vulnerable to imbalanced bone health, but they’re not the only ones at risk.
Other factors that affect the bone structure and calcium balance are:
- high alcohol intake
- high coffee intake
- imbalanced diets, for example, high protein and low minerals
- consuming soft drinks on a regular basis
- low weight-bearing exercise
- limited exposure to sunlight (for vitamin D)
- hormonal imbalances
- imbalance of thyroid function
- certain medications for example steroids
Pregnancy is a time where sufficient calcium intake is of prime importance because of the needs of the baby. If calcium intake or absorption is low calcium will be leached from bones and teeth to strengthen baby’s growing bones and teeth, heart, muscles and nervous system. Sufficient calcium tissue levels during this special stage of life is therefore important for the health of mother and baby.
The importance of calcium absorption factors
There are two aspects affecting calcium levels. First is calcium intake and second is how well the body can absorb this calcium. Calcium absorption is an important consideration, because this governs the amount of calcium available to the body for bone mineralisation and other key functions. Simply taking a high dose calcium supplement is not an effective solution. There are health risks associated with elevated blood calcium levels, so it’s important to look at all the cofactors needed for absorption and to not take exceedingly high dosages, or normal doses for long term.
If calcium absorption is poor, intake of high dosages of calcium may lead to calcification meaning development of deposits in places, such as kidney stones, plaques in blood vessels or accumulating in heart valves and restricting blood flow.
Maximising calcium absorption for optimal health
Essential to correct calcium absorption is adequate levels of:
- hydrochloric acid production in the stomach
- dietary intake of healthy fats
- vitamin D and k
Hydrochloric acid production in the stomach is the first influential factor in calcium absorption. If it is too little (a condition common to people eating modern diets) the calcium remains out of solution and cannot be assimilated into the intestines for absorption. This is such an important and prevalent factor in developed countries that it can result in up to 80% loss of available calcium absorption.
Studies have found that calcium absorption rate increases when the diet includes a healthy balance of beneficial fats together with a balanced ratio of fibre, carbohydrates and proteins.
Vitamin D (as calcitriol, regulated by the parathyroid hormone) regulates intestinal calcium absorption, controlling how much is converted into bone tissue. Our bones are the body’s reservoir of calcium stores. If dietary calcium intake is inadequate then Vitamin D signals the body to increase calcium absorption from the small intestine and to release calcium from bone to maintain blood calcium levels. This may lead to imbalanced bone tissue composition over time.
Recent studies reveal up to 40% of the New Zealand population gets insufficient levels of vitamin D, indicating supplementation may be required.
Read more about Vitamin D – here.
Also important is the correct balance of magnesium to calcium. A ratio of 2:1 – 1:1 calcium to magnesium is needed by the body for optimal functioning.
Read more about Magnesium – here.
Adequate levels of the trace mineral boron (found in fruits, vegetables and nuts) have been shown in a study of post-menopausal women to prevent calcium loss and bone demineralisation.
Silica is important because it enhances absorption of all other minerals in the body, in particular remineralisation of bones and all structural tissues in the case of calcium. As we age our silica levels decline. Good food sources of silica include raw oats, oat straw tea, horsetail tea, beetroot and alfalfa. Women having babies at a later age may need to supplement silica as part of their nutrition plan.
Low Vitamin K intake is linked to increased risk of imbalanced bone health. Vitamin K is required for formation of osteocalcin, the calcium-binding bone matrix protein.
Excessive dietary fibre, sodium, phosphorus and caffeine can reduce calcium absorption.
What is the recommended total daily calcium intake?
These figures are the NZ minimum recommendations for total calcium intake from all sources. Children need plenty of calcium-rich food in their daily diet to provide for a growing skeleton, especially through their teenage years. Children’s recommended daily intake guidelines are 500 mg from 1 – 3 years, 700 mg from 4 – 8 years, 1000 mg from 9 – 11 years and teenagers 1300 mg from 12 – 18 yrs. 1000 mg per day is generally recommended for adult women up to menopause, and men up to age 70.
Calcium intake during pregnancy is most important for the health of the mother as well as the proper development of the baby. The NZ recommended daily intake is 1000 mg to 1300 mg per day.
It is important though to not only think about intake of additional calcium but also about how well calcium is used in the body: hormonal changes and vitamin D deficiency for example, which can occur in these stages of life, can influence how calcium metabolism in the body. So instead of taking higher dosages of calcium, it is beneficial to consider all the cofactors as well. A health professional will be able to give guidance on the best use of supplementation.
Are you getting adequate bioavailable calcium from your regular dietary intake?
A balanced diet and lifestyle is a good way to increase your intake of calcium. The range of foods containing good bioavailable sources of calcium is not as limited as you might think.
Calcium-rich foods include:
– Parsley, raw
– Chinese cabbage, boiled
– Red Cabbage, boiled
– Celery stem, raw
– Leek, boiled
– Lettuce, Mixed leaf variety, raw
– Spring onion, raw
330 mg per 100 gm
88 mg per 100 gm
53 mg per 100 gm
56 mg per 100 gm
61 mg per 100 gm
61 mg per 100 gm
140 mg per 100 gm
|Dried beans and legumes:
– Green beans, boiled
– Haricot beans, boiled
– Red Kidney beans, boiled
37 mg per 100gm
65 mg per 100gm
31 mg per 100gm
– Sardines, canned
– Salmon, red, canned
– Tarakihi, baked
550 mg per 100 gm
93 mg per 100 gm
25 mg per 100 gm
|Nuts & seeds:
– Sesame seeds, raw
– Sunflower seeds, raw
– Brazil nuts, raw
– Hazelnuts, raw
– Peanut butter
– Pistachio nuts, raw
975 mg per 100 gm
116 mg per 100 gm
68 mg per 10 nuts
179 mg per 100 gm
32 mg per 100 gm
135 mg per 100 gm
– Camembert cheese
– Colby Cheese
– Milk, standard
170 mg per ¼ round
650 mg per 100 gm
166 mg per 100 ml
It is best to talk to a health professional to discuss concerns regarding calcium deficiency