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We need to know more about calcium supplementation: Why menopausal women need more nutrients for bone health; do coffee, grains and sugar affect bone health; why do so many people suffer from osteoporosis and why is it more common in women; and how can we maintain the correct ratio of minerals and vitamins that are needed for optimal bone health? Natural Medicine magazine asks clinical nutritionist Mark Timon for answers to these burning questions.
1. What is a plant calcium and how does its potency differ from other supplemental calciums?M.T. Plant-based calcium comes from living nature. It is part of the biomass of the plant, held within the roots, leaves, stem and fruits. In plants, elemental calcium is attached to complex carbohydrates, bioflavonoids, fibres, and/or proteins.
Synthetic calcium compounds are made in clean laboratories usually as the result of common acid-base reactions. A simple, molecular calcium compound is formed by adding inexpensive, purified calcium oxide to an acid solution.
In general, calcium from plant-based supplements should be more thoroughly absorbed and rapidly delivered into the bloodstream, i.e. more bioavailable. However, the elemental potency of calcium in plant foods will necessarily be far lower than the elemental potency of synthetic calcium compounds. For example, calcium carbonate is about 36% elemental calcium, calcium ascorbate is about 10% calcium, and some other compounds can run as low as 4% elemental calcium. A typical plant with a relatively high biomass of elemental calcium will run between 1.5% and 2% elemental calcium after the plant has been dried
and powdered. Hydrilla verticillata is a unique plant that hyper-accumulates mineral compounds. Its elemental calcium content on a dry weight basis can reach 15% if the soil is rich in calcium.But the biological value of calcium cannot be determined solely on the elemental content of the source material. Calcium carbonate (36% elemental) is renowned for having the lowest bioavailability among all other supplemental forms when tested in humans over the age of 30. Calcium citrate, calcium citrate-malate, Krebs cycle calcium, and some amino acid chelates are far more worthwhile sources of calcium. Nevertheless, plant calcium from Hydrilla has demonstrated superior bioavailability in unofficial, anecdotal reports. Calcium from other plants, including spinach and broccoli, show similarly superior bioavailability.
There is one new form of alleged plant- derived calcium that can be viewed as a hybrid between a purely plant calcium and a synthesised calcium. It is a form of calcium carbonate synthesised by the tendrils of the North Atlantic sea algae, Lithothamnium. This unique species precipitates calcium carbonate out of ocean water to form a protective shell around the delicate tendrils of the plant. Lithothamnium’s calcium carbonate also contains trace amounts of other minerals and substances present in the seawater yet still contains around 32% elemental calcium. Although synthetic calcium carbonate has a long history demonstrating low to no bioavailability in humans, the processors and marketers of Lithothamnium calcium carbonate claim that it has high bioavailability. Early tests confirm good absorption, but more work has to be done to absolutely verify that the delicate Lithothamnium algae has overcome the innately poor bioavailability of pure calcium carbonate.
2. Does it matter which form of calcium one takes?M.T. Ultimately, it does matter. At the bottom of the list, or rather not on the list, should be purified calcium carbonate, eggshell calcium, oyster shell calcium and coral calcium, all of which are minimally different forms of calcium carbonate. Initial claims of high bioavailability for all of these materials by the purveyors of the raw material have ultimately been proved false. The most bioavailable forms instead include legitimate plant calciums, Krebs cycle calcium, calcium orotate, calcium citrate-malate, true, fully reacted calcium amino acid chelate and calcium aspartate.
3. Are there any side effects from taking a plant calcium?M.T. Plant calcium is the most benign form of calcium to ingest. It lacks any acidic overload associated with a synthetic compound that might be encountered from dissociation of an acid ligand as the elemental calcium is separated and readied for absorption. Even in those persons who can absorb calcium from calcium carbonate, it has been demonstrated that no biological benefit will be derived, and certainly no additional calcium deposited into bone tissue due to the accompanying uptake of carbonic acid from dissociated CaCO3.
Individuals may also exhibit a variety of side effects to the ingestion of synthetic forms of calcium including mild constipation, digestive disturbance (gas), muscle cramping, or fatigue. Plant calcium, on the other hand, may have one notable side effect, and that could be muscle cramping. The symptom reflects the innate imbalance of calcium to magnesium in all known plants rich in calcium. Absorbing calcium from any source without a balancing amount of magnesium will result in muscle cramps as a simple fact of human biochemistry.
4. Calcium is well known as a bone nutrient but few seem to know about the need for boron and vitamin D3. Why does one need to supplement with all three?M.T. Calcium is not the sole contributor to bone health. The mineral portion of bone is made up of large molecular crystals of a substance called hydroxyapatite. Hydroxyapatite contains calcium, phosphorus, magnesium, silicon, strontium, zinc and, because we all live in a contaminated world, lead and perhaps some other contaminants reflective of a person’s local environment. In the final analysis, healthy bone usually runs between 60 to 70% mineral, 10 to 20% water and up to 30%, or a little more, collagen with trace amounts of other proteins and inorganic salts.
Nutrients essential for the formation of healthy bone absolutely include calcium, the most dominant mineral (1.5 times more calcium than phosphorus). But we should not forget vitamin D, without which calcium cannot be absorbed from the digestive tract, or zinc, for zinc plays a part in activating enzymes necessary for the construction of the hydroxyapatite crystals.
Vitamin DAs recommended intakes have increased, epidemiological studies have made it evident that major segments of the world population do not actually take in or manufacture enough vitamin D unless they live in sunny regions of the world where adequate vitamin D can be manufactured by the skin. Of course, one must get outside and not use sunscreen for skin synthesis to be successful. As a result, it is recommended that persons living in temperate zones of the world where the climate is cooler and the skies cloudier, or those whose occupations keep them indoors during daylight hours, should take supplemental vitamin D. The latest research data indicate the following dosages to be appropriate: ■ Infants: 1 000 i.u. per day■ Children & teenagers: 2 000 i.u. per day■ Adults: 2 000 to 4 000 i.u. per day■ Seniors: 4 000 to 10 000 i.u. per day.
Boron has an indirect role to play in the health and formation of bone. Boron is necessary to both create and sustain hormonal homeostasis among dehydroepiandrosterone (DHEA), androgens, oestrogens, and the hormonal form of vitamin D, calcitriol. Without sufficient boron in the diet, ratios of these related hormones will become unbalanced. We know that the androgen, testosterone, and calcitriol, as well as oestrogen, help drive calcium into bone. DHEA is a neuter hormone that plays no direct role in bone formation until needed. If a person needs some extra androgens to achieve proper balance, DHEA will be converted into those androgens. If extra oestrogens are needed to achieve proper balance, DHEA will be converted into those oestrogens. Boron helps maintain the proper balance. Without it, conversion, synthesis and activity of the hormones necessary to build strong bone will lag.
Neither boron nor potassium is stored in the human body. They come in and go out with equal rapidity. The implication is that one must be sure to take in at least 3 mg of elemental boron each day, as far as bone health is concerned. Modern diets provide only 1 to 1½ mg, however. It appears supplementation is necessary in order to maintain hormonal homeostasis and bone health
5. Is there anything else one can do for bone healthM.T. There is much one can do. The adage, ‘use it or lose it,’ is often touted as the primary remedy for bone loss. As a person places physical force against the skeleton, stressing it through exercises such as walking, running, and, significantly, weightlifting, electrical charges are triggered across the surface of the bone that help draw minerals to it. Dietary habits can work against bone health or work in favour of bone health. Consumption of confectionery foods, grains, and (this almost seems counterintuitive) dairy products create a profoundly acidifying burden on human metabolism that overruns the bicarbonate buffering system in the blood, and forces the release of mineral from bone in order to neutralise the acid load. Indeed, grains, refined sugars and dairy foods are the worst culprits along with consumption of more than 2 cups of coffee per day.
Eliminating or restricting grains, sugars and dairy foods in favour of vegetables is a better tactic. Diets rich in vegetables with moderate meat intake create a net alkaline balance that preserves bone tissue.
6. Can one’s bone density and tensility be improved with supplementation?M.T. Yes. Following the dietary recommendations above along with calcium, vitamin D, zinc, boron and vitamin C supplementation plus weight-bearing exercise can improve bone density and tensile strength.
7. How long does bone take to regenerate? Can bone regeneration be speeded up?M.T. Under normal circumstances, the human skeleton is replaced every seven years. However, osteoblast (bone-building activity) and osteoclast activity (osteoclast cells break down bone) can be altered within hours of changing the diet and supplementation. For example, when we retire for the night, and the pull of gravity is greatly reduced as we stretch out in a prone position, osteoclast activity is stimulated while osteoblast activity is suppressed. However, it has been shown that taking supplemental doses of calcium and vitamin D at night stimulates osteoblast (bone building) activity.
8. Is it important to focus on building stronger bones when one is young?M.T. Absolutely! Approximately 1% of bodily calcium must be kept in solution in the bloodstream to sustain normal biochemistry. If the precise amount of calcium cannot be maintained from dietary intake, calcium will gradually be liberated from the bone in order to maintain the essential blood calcium levels.
Age-related changes in digestive and hormonal function lead women by age 30 and men by age 40 to slip into ‘negative calcium balance.’ This is the state where a person loses more calcium through the urine than is absorbed from the digestive tract. In order to maintain required blood levels of calcium, the absorptive shortfall associated with ageing creates a daily net loss of bodily calcium that reduces bone mass over time. Therefore, it is critically important that a young person build deep and rich stores of calcium in their bones while digestive capabilities and hormonal functions are running at their peak prior to reaching middle age.
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