Food Sources

• Dairy products:
  • such as milk, yogurt, cheeses, and buttermilk contain a form of calcium that your body can absorb easily.

  • Yogurt, most cheeses, and buttermilk are excellent sources of calcium and come in low-fat or fat-free versions.

  • Milk is also a good source of phosphorus and magnesium, which help the body absorb and use calcium.

  • Vitamin D is needed to help the body use calcium. Milk is fortified with vitamin D for this reason.

• Whole milk (4% fat) is recommended for children ages 1 to 2.
• Adults and children over the age of 2 should drink low-fat (2% or 1%) or skim milk and other dairy products.
• Removing the fat will not lower the amount of calcium in a dairy product.

DIETARY SUPPLEMENTS

• Calcium is also found in many multivitamin-mineral supplements.
• Dietary supplements may contain only calcium or calcium with other nutrients such as vitamin D. 
• Check the label on the Supplement Facts panel to determine the amount of calcium.
• Calcium absorption is best when taken in amounts of no more than 500 mg at a time.

• Two commonly available forms of calcium dietary supplements include citrate and carbonate.​
  • Calcium citrate is the more expensive form of the other supplement. It is taken up well by the body on a full or empty stomach.
  • Calcium carbonate is less expensive. It is absorbed better by the body if taken with food. 

Side Effects

Increased calcium for a limited period of time does not normally cause side effects. However, receiving higher amounts of calcium over a long period of time raises the risk of kidney stones in some people.

Those who do not receive enough calcium over a long period of time can develop osteoporosis (thinning of bone tissue and loss of bone density over time).

Tell your health care provider about any dietary supplements and medicines you take. Your provider can tell you if those dietary supplements might interact or interfere with your prescription or over-the-counter medicines. In addition, some medicines might interfere with how your body absorbs calcium.

The concentration of calcium in the body tends to decline as we age because it is released from the body through sweat, skin cells, and waste.

• in addition,as women age, absorption of calcium tends to decline due to reduced estrogen levels.
• calcium absorption can vary depending on race, gender, and age.

Recommendations

• The preferred source of calcium is calcium-rich foods such as dairy products. Some people will need to take calcium supplements.
• The Recommended Dietary Allowance (RDA) for vitamins and minerals reflects how much of each vitamin or mineral most people should get each day. 
• How much calcium you need depends on your age and gender. Other factors, such as pregnancy and illnesses, are also important.

Infants (Adequate Intake):

0 - 6 months: 200 milligrams per day (mg/day)

7 - 12 months: 260 mg/day

Children and Adolescents:

​1 - 3 years: 700 mg/day

4 - 8 years: 1,000 mg/day

9 - 18 years: 1,300 mg/day

Adults:

19 - 50 years: 1,000 mg/day

50 - 70 years: Men - 1,000 mg/day; Women - 1,200 mg/day

Over 71 years - 1,200 mg/day

Pregnancy and Breast-feeding:

14 - 18 years: 1,300 mg/day

19 - 50 years: 1,000 mg/day

The following list can help you determine how much calcium you are getting from food:

• 8-ounce glass of milk = 300 mg of calcium

• 2 ounces of Swiss cheese = 530 mg of calcium

• 6 ounces of yogurt = 300 mg of calcium

• 2 ounces of sardines with bones = 240 mg of calcium

• 6 ounces of cooked turnip greens = 220 mg of calcium

• 3 ounces of almonds = 210 mg of calcium

Vitamin D is needed to help the body absorb calcium. When choosing calcium supplements, look for ones that also contain vitamin D.

Magnesium and Healthful Diets

The Dietary Guidelines for Americans describes a healthy diet as one that:

• A variety of fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products.
  Whole grains and dark-green, leafy vegetables are good sources of magnesium. Low-fat milk and yogurt contain magnesium as well. Some ready-to-eat breakfast cereals are fortified with magnesium.

• Includes lean meats, poultry, fish, beans, eggs, and nuts.
  Dried beans and legumes (such as soybeans, baked beans, and peanuts) and nuts  provide magnesium.
• Is low in saturated fats, trans fats, cholesterol, salt (sodium), and added sugars.
• Stays within your daily calorie needs.

Side Effects

Side effects from increased magnesium intake are not common because the body removes excess amounts. Magnesium excess almost always occurs only when magnesium is supplemented as a medication.

Lack of magnesium (deficiency) is rare. The symptoms include:

• Hyperexcitability
• Muscle weakness
• Sleepiness

Deficiency of magnesium can occur in people who abuse alcohol or in those who absorb less magnesium due to:

• Burns
• Certain medications
• Low blood levels of calcium
• Problems absorbing nutrients from the intestinal tract (malabsorption)
• Surgery

Symptoms due to a lack of magnesium have three categories.

Early symptoms:

• Anorexia
• Apathy
• Confusion
• Fatigue
• Insomnia
• Muscle twitching
• Poor memory
• Reduced ability to learn

Moderate deficiency symptoms:

• Heart (cardiovascular) changes
• Rapid heartbeat

Severe deficiency:

• Continued muscle contraction
• Numbness
• Seeing or hearing things that aren't there (hallucinations)