Supplements

By: Red Hot Mamas

Published: September 27, 2006

The Calcium Connection

Calcium is a very important mineral for the human body.  It is essential to maintain an adequate intake of calcium for healthy bones and teeth.  It is available in many forms and has many names (calcium carbonate, calcium gluconate, calcium caseinate, calcium citrate, calcium phosphate, etc.).

A constant supply of calcium benefits your body by:

• Providing support for bone structure

• Promoting muscle contraction

• Expanding and contracting blood vessels

• Aiding in the secretion of hormones and enzymes

• Sending messages through the nervous system

Calcium is the most abundant mineral in the human body and 99% of it is stored in our bones.  Calcium becomes increasingly important during menopause as women face an increased rate of bone loss and an increase in the risk for osteoporosis.  It is common for women in menopause to increase their intake of calcium to prevent further breakdown of bone.

Calcium Intake

Unfortunately, many people are not meeting their recommended intake for calcium.  A calcium deficiency can occur in people with certain diseases and can also lead to osteoporosis .  This type of deficiency can cause bones to become weak and brittle.  A lack of calcium can also induce muscle spasms, cramping and even seizures.

A low calcium intake, poor calcium absorption or excess calcium secretion can all lead to osteoporosis .  The adequate intake for calcium recommended by the National Institutes of Health (NIH) is as follows:

• Perimenopausal women ages 25-50:  1,000mg/day

• Postmenopausal women younger than age 65 and using estrogen therapy: 1,000mg/day

• Postmenopausal women younger than age 65 and not using estrogen therapy: 1,500mg/day

• All women older than age 65:  1,500mg/day

The milk, yogurt and cheese group of the US Department of Agriculture’s Food Guide Pyramid recommends 2-3 servings of dairy per day.  One serving is the equivalent of 1 cup of milk, 8 oz. of yogurt, 1.5 oz. of natural cheese (i.e., American) or 2.0 oz. of processed cheese (i.e., American).

Some other foods that contribute to overall calcium intake include non-fat and reduced fat dairy products and those listed below.  Calcium-fortified foods are available as options also.  This is a good option for lactose-intolerants or vegans.

Selected Food Sources for Calcium from the US Department of Agriculture Nutrition Database

TABLE 1

Calcium Absorption

Merely taking in calcium-rich foods or supplements is not enough!  There is another process that is just as important, digestion and absorption.  For postmenopausal women by age 65, calcium and vitamin D absorption decreases to less than 50% of that in adolescents.

There are actually a number of other vitamins and minerals that work together to ensure your body is absorbing the calcium you take in.  Some additional things to think about to help you maintain proper levels of calcium in the body are vitamin D, magnesium, calcium, phosphorous and many more.

Calcium absorption is negatively affected by the following list.  When making a conscious effort to take calcium and absorb it efficiently, avoid these things:

• Soft drinks

• High fiber diets

• Coffee/caffeine

• Excessive intake of oxalic acid (found in spinach and some other greens)

• Excessive intake of phytates (a type of fiber found in wheat bran and some other grains)

• Excessive amounts of fats

• Sugar

• Salt

• Alcohol

• Smoking

Magnesium

Magnesium is an essential for hormone, enzyme, muscle functioning, bone mineralization and a metabolic activity of cells. However, it may not be as necessary for bone health or absorption of calcium as we once suspected.

Most of the studies on bone mineral density and fractures due to osteoporosis were based on the benefits of calcium without magnesium supplementation.  In addition, a study on postmenopausal women’s calcium absorption found that when magnesium intake was double the daily recommended average, there was no effect.

The North American Menopause Society (NAMS) still recommends magnesium supplements for frail, elderly women and women with gastrointestinal disease.  A sufficient intake of magnesium for women 50 and over is 320 mg per day that can be easily achieved through diet.  Wheat products, whole-grain breads, cereals, pastas, nuts, leafy green vegetables, meats and milk are good sources of magnesium.

Phosphorous

The ratio of calcium to phosphorus is important for proper bone health. These two nutrients work together in a symbiotic relationship. Think of phosphorus as calcium’s companion mineral, accounting for approximately one third of bone mineral.

If you take too much calcium in the absence of phosphorus, it will bind what little phosphorus is present in the intestines, blocking its absorption and make it unavailable for bone building.  In turn, excess phosphorus and too little calcium can impair the body’s ability to use calcium.

The key is a balanced intake of both minerals. And yet, this recommendation has been largely ignored, both by the scientific community and by calcium supplement manufacturers, largely because it is assumed that most people get enough phosphorus from their diet, when, in fact, they may not.

The typical American diet contains more phosphorus than calcium, the former being derived largely from meats, dairy products and carbonated soft drinks.  The body’s ability to absorb this phosphorus can be substantially decreased when extra calcium is taken as a supplement, especially with meals, without the corresponding supplemental phosphorus. The scenario is particularly prevalent in women with restricted diets of meat and dairy.

A calcium/phosphorus imbalance can have particularly negative consequences for post menopausal women with osteoporosis, a subgroup that tends to have low dietary phosphorus intake. Low phosphorus levels have been found to jeopardize bone-building treatments in these women.

When you add high doses of calcium citrate or calcium carbonate – frequent co-therapies along with prescription medication – to increase bone density, the risk of phosphorus deficiency may arise, thus limiting bone gain.

A calcium phosphate supplement taken with food ensures ample phosphorus as well as calcium to support bone building. Surprisingly though, few supplements or fortified foods contain added phosphorus.

The recommended daily intake of phosphorous for women ages 50 and older is 700mg per day.  Food sources include milk, yogurt, cheese, peas, meat, eggs, and some cereals and bread.

Vitamin D

Vitamin D makes it possible for your body to absorb calcium.  Vitamin D helps maintain normal levels of calcium and phosphorous in your bloodstream.  It is also benefits your bones by promoting bone mineralization.  Without vitamin D, bones can become brittle, thin or misshaped.

Your body can make vitamin D after exposure to sunlight or through foods.  “Catching some rays” can actually help trigger vitamin D synthesis in your skin.  About 15 minutes of sun exposure on the hands, arms or face two to three times a week can help.  For women who cannot sit in the sun, vitamin D can be obtained through meals or supplements.

The recommended dosage of vitamin D for women between the ages of 51 and 69 years is 10µg (400 IU) per day.  For women 70 years and older, intake should be 10 to 20µg (400 to 800 IU)
per day.  Doses of vitamin D should not exceed 25µg (1,000 IU) per day because it can turn toxic if overused and produce a loss of calcium in bones.

Selected food sources of vitamin D developed by the USDA

Table 2

If you cannot make friends with a cow, calcium supplements that include vitamin D are also available.

Calcium and vitamin D in the news:

In the Spotlight: Calcium and Vitamin D