Bay Area Medical Information (
Calcium and Vitamin D:
Facts that can make a difference

Broccoli and Nonfat Milk are good sources of calciumCalcium works in concert with Vitamin D to form and maintain strong bones, yet calcium and vitamin D deficiency is widespread in the United States and worldwide. This is especially true for adults 50 years and older, and accounts for the development of osteoporosis and osteoporosis-related fractures.

Are you getting enough calcium and Vitamin D? The new National Osteoporosis Foundation guidelines for both men and women are:

    • Calcium: Adults under age 50 need 1,000 mg of calcium daily, and adults age 50 and over need 1,200 mg of calcium daily.

    • Vitamin D: Adults under age 50 need 400-800 IU of vitamin D3 daily, and adults age 50 and over need 800-1,000 IU of vitamin D3 daily. Your doctor can check a blood test to find out if you're getting enough Vitamin D.(5) New research suggests that Vitamin D supplementation might protect against diabetes, gum disease, multiple sclerosis, peripheral neuropathy, osteoporosis, and possibly cancer, stroke, and heart disease. Based on this new research, vitamin D has been recognized in the Dec. 2007 issue of Time magazine as "one of the top 10 medical breakthroughs of 2007". Read more about Vitamin
Recommended Calcium Intakes (mg/day)
National Academy of Sciences (1997)
Ages mg/day
Birth-6 months 210
6 months-1 year 270
1-3 500
4-8 800
9-13 1300
14-18 1300
19-30 1000
31-50 1000
51-70 1200
70 or older 1200
Pregnant or lactating
14-18 1300
19-50 1000

Calcium in Foods

Calcium in foods, especially from milk and milk products, has been found to be better absorbed than from supplements (4).  Milk products include hard cheese, cottage cheese, yogurt, green vegetables and spinach.  A simple way to estimate one's daily intake of dietary calcium is to multiply the number of dairy servings consumed each day by 300 mg. A postmenopausal woman would need five servings per day of calcium-rich foods.  One serving equals 8 oz of milk or yogurt, 1 oz of hard cheese, 16 oz of cottage cheese, or 2 cups of broccoli. Despite all efforts to eat a calcium-rich diet, if dietary intake of calcium remains below the recommended value, calcium supplementation is recommended:

Calcium tablets1) Calcium citrate or citrate malate is generally thought to be better absorbed and more effective than calcium carbonate. Although calcium carbonate is one of the least expensive forms of calcium and is the most common commercial calcium supplement, it can cause constipation and bloating, and it may not be well absorbed by people with reduced levels of stomach acid, such as many people over age 50(3). Citracal (calcium citrate) with Vitamin D is recommended by many health care providers.

2) Tums (chewable calcium carbonate) is also recommended in those who are younger(3).

  • Food intake affects absorption of each form of calcium differently:
    • Tums are best absorbed with food;
    • Citracal is best absorbed without food. Bedtime is frequently an ideal time to take Citracal as people most often have an empty stomach and bedtime dosing of calcium is also thought to help with sleep.

  • Do not take more than 500 mg of calcium at a time. If more needs to be taken, spread out the doses during the day in divided doses.    Doses any larger than 500 mg will not be absorbed.  Additionally, foods labeled as containing 100% of the recommended dietary value of calcium should not be considered as the single source of a full day's supply of calcium.
  • Take calcium supplements with Vitamin D Calcium supplements are available with Vitamin D added.

  • Calcium supplements can block the absorption of certain medications. If you are also taking tetracycline, fluoroquinolones (such as Cipro, etc) iron, levothyroxine (thyroid medicine), or any medication to be taken on an empty stomach, take the oral calcium supplement at a different time of the day. For instance, take the thyroid medicine at 6am, and then take the calcium tablet later in the day(2)(5).   It is important to talk with your health care provider about possible interactions between prescription or over-the-counter medications and calcium supplements.

  • Certain foods and medications can decrease the absorption of calcium: Corticosteroids and foods such as rhubarb, spinach, and bran can interfere with the absorption of calcium. Take the calcium at a different time of the day.

  • Constipation can be a side effect of calcium supplementation : While some people tolerate supplements well, others have difficulty with side effects, such as gas or constipation. The best way to absorb calcium with the least risk of constipation is to get most of it from foods such as low-fat dairy products and fortified orange juice, otherwise, you may want to try one or more of the following to overcome the constipation related to a calcium supplement:
    • Maintain a regular exercise regimen
    • Increase fruits, vegetables, and high fiber foods in your diet;
    • Drink two to four extra glasses of water a day;
    • Eat 1-3 prunes and/or bran cereal every morning followed by a warm drink;
    • Ask your health care provider about taking calcium supplements with magnesium added (i.e. Citracal Plus w/Magnesium) to minimize the constipation. Dietary magnesium does not pose a health risk in most people, although risk of magnesium toxicity increases in patients with kidney failure. Also, very large doses of magnesium-containing laxatives and antacids also have been associated with magnesium toxicity.
    • Take a regular preparation of a water-soluble fiber (methylcellulose) such as Citrucel.
    • If all else fails, take a mild over-the-counter stool softener (Colace) every day.

  • Do not take any supplements with bone meal or dolomite calcium. Bone meal calcium comes from animals' bones. Any heavy metals the animal has ever been exposed to are stored in the bones. Commercial samples of supplements with bone meal or dolomite has been analyzed by different laboratories, and significant amounts of lead, arsenic, mercury, and other potentially toxic metals were detected.


1) Osteoporosis Overview from the National Institute of Health
2) Osteoporosis: A debilitating disease that can be prevented and treated from the National Osteoporosis Foundation
3) Milk intake and bone mineral acquisition in adolescent girls: British Medical Journal, 315, 1997
4) Effect of CalciumCarbonate on the Absorption of Levothyroxine JAMA. 2000;283:2822-2825 5) Vitamins and Minerals, Nurse Practitioner Prescribing Reference, Winter 2006-2007
6) Dietary Supplement Fact Sheet: Vitamin D from the Office of Dietary Supplements, National Institute of Health

7) National Osteoporosis Foundation’s Updated Recommendations for Calcium and Vitamin D3 Intake. from the National Osteoporosis Foundation.
8) Vitamin D Deficiency Associated with Weakness in Older Patients from MedPage Today/J Gerontol A Biol Sci Med Sci 2007
9) Vitamin D Fact Sheet from the Office of Dietary Supplements, National Institute of Health
Vitamin D Benefits from Sun Exposure Outshine Cancer Risk from MedPage Today
11) Cancer Meta analyses Shine on Vitamin D from MedPage Today

Written by N Thompson, ARNP, MSN and M Thompson MD, last updated July 2008

~Make your home page and gateway to the World Wide Web~
This is an up-to-date educational source for patient education. Health care providers may feel free to print out copies for their patient's use. Please note that content may not be copied for resale or other commercial use such as for web sites. The content on this site is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment.   Never disregard professional medical advice or delay in seeking it because of something you have read on this site. 
Home | About Us | Advertise | Contact Us |Terms of Use | Privacy Policy
©2015 Bay Area Medical Information (™ All Rights Reserved
Google |Yahoo |  MSN |  AOL |  Netscape |  Earthlink |  Dogpile |  All the Web | AltaVista