CALCIUM: ANOTHER WEIGHT LOSS STRATEGY

CALCIUM AND VIT D SUPPLEMENTATION

CALCIUM CUTS BONE LOSS

VITAMIN C - THE WONDER CURE

PMS - PROPER MULTIPLE SUPPLEMENTATION

CATARACTS AND ANTIOXIDANTS

CALCIUM & MAGNESIUM

A CRAMP "SOLUTION"

CHOCOLATE CRAVINGS

CHELATION & MINERAL BIOAVAILABILITY

MALNUTRITION AND THE ELDERLY

MAGNESIUM: ARE YOU "MARGINALLY" DEFICIENT?

MAGNESIUM: THE MEDICINAL MINERAL

YOUR HEALTH CARE DEBATE

THE OTHER DEBATE

"TIS THE SEASON TO BE STRESSED"

VEGETARIANISM: A 90'S APPROACH TO A HEALTHIER LIFESTYLE

WINTER BLUES AND HOLIDAYS

ANTIOXIDANT PROTECTION

SHOULD YOU TAKE EXTRA VITAMINS

MACULAR DEGENERATION STUDY SUPPORTS SUPPLEMENTATION

WHAT DO HEART DISEASE, STROKES AND ALZHEIMER'S HAVE IN COMMON? 3 B VITAMINS

Calcium's benefits and dietary sources are well known. It is also known that magnesium is an enzyme cofactor which facilitates calcium's passage across cell membranes. Less understood is how calcium and magnesium interact. And, while there might be agreement on "adequate" levels of calcium and magnesium intake, there are few opinions on the optimal ratio of calcium to magnesium.

The Critical Balance
Given the calcium-poor and magnesium-rich environment of our evolutionary predecessors, (i.e. our ancestors 6,000 years ago), the human body developed mechanisms to shore calcium and excrete excess magnesium. Today, two hormones play an important role in calcium metabolism - calcitonin("CT") and parthyroid hormone ("PTH"). CT increases calcium deposits in the bone matrix. PTH favors calcium uptake in soft tissues. (Excessive calcium accumulation in soft tissues eventually leads to irreversible cell damage.) Magnesium suppressed PTH and stimulates CT. Hence, it helps put calcium into bones - preventing osteoporosis, and helps remove it from soft issues - eliminating some forms of arthritis.

However, a delicate balance between magnesium and calcium exists, since high calcium intakes suppress magnesium absorption. Hence, large calcium intakes may contribute to its own malabsorption or magnesium deficiency.

Calcium can collect in the soft tissues causing what appears as a calcium deficiency, when in fact, we may have more than an adequate supply of calcium. The internaional Clinical Nutritional Review published experiments in which volunteers on a low magnesium diet were given both calcium and vitamin D supplements. All subjects were magnesium-depleted and although they had been given adequate supplements, all but one became calcium deficient. When given calcium intravenously, calcium blood levels rose, but only during the intravenous feeding. By adding magnesium, their magnesium levels rose and stabilized rapidly, and calcium levels also rose within a few days - although no additional calcium had been taken.

"Adequate" Intake
How much calcium and magnesium is "adequate" and what dietary supplementation is appropriate? The National Research Council ("NRC") of the National Academy of Sciences establishes recommended daily allowances ("RDA") which are updated periodically. (For labeling purposes, the FDA has based US RDA's on the NRC's 1968 RDA tables.) The RDA"s are believed to be adequate to meet needs of healthy individuals. The following indicates the 1989 RDA's for men and women aged 25 and over:

*1,200mg for post-menopausal women

Ideally, an individualized (and time-consuming) diet analysis can determine how to change diet or to supplement to obtain an adequate daily intake. Consider the average American diet. Studies have found that the average American adult consumes approximately 400mg of calcium and 240mg of magnesium daily.

Reliable dietary sources of calcium are well known. Important magnesium food sources are whole grains, nuts and legumes. However, measuring intake based on consumption of these food sources may be misleading, since magnesium content in these foods is based upon the soil's magnesium content. Magnesium has suffered leaching from soil due to potassium-based fertilizer, therefore it is unclear whether these are reliable sources of magnesium. Moreover, consumption of refined sugars and alcohol causes urinary excretion of magnesium. Therefore, the average American adult may be consuming 400mg of calcium but intakes miniscule amounts of magnesium in his/her diet. It could be argued that supplementation should be at least 400 mg of calcium and 350 mg of magnesium (approx. a 1::1 ratio) for the average American adult to obtain adequate calcium and magnesium amounts.

Many individuals fall within a calcium-deficiency risk group such as the elderly, diabetics, strenuous exercisers, pregnant women, those on diuretics, alcohol consumers, lactose intolerant people and dieters of all kinds (low calories, high protein, high fiber and low fat). This last risk group is becoming more prevalent, since most dietary calcium is obtained from dairy products - many of which are high fat food sources. Therefore, those individuals who fall into a calcium-deficient risk group and who may not intake adequate amounts of magnesium, should supplement at least 800 mg of calcium and 350 mg of magnesium daily (approx. a 2::1 ratio) to obtain adequate levels of each.

The Optimal Ratio?
The RDA's do not address optimal amounts of these essential nutrients or the optimal ratio of calcium to magnesium. Few studies "prove" and few experts advocate an optimal ratio of calcium to magnesium. Dr. Guy Abraham, MD, a research gynecologist and endocrinologist in PMS and osteoporosis advocates taking calcium to magnesium in a 1::2 ratio. This is based on his research suggesting that women with osteoporosis have a deficiency of a chemical that is made when they take twice as much magnesium as calcium. He found that when calcium intake is decreased, it is utilized best than when it is high. Nonetheless, there is no widely accepted optimal ratio of calcium to magnesium.

A FINAL NOTE
Despite magnesium's critical role in calcium absorption, people with renal failure and high grade atrioventricular blocks should not take supplemental magnesium. Individuals should consult a physician/certified nutritionist or conduct their own diet analysis to determine their own levels of calcium and magnesium intake and supplementation.

Copyright © April - May, 1992