NOVEMBER 16, 2020
In my last blog post, I discussed the importance of strong bones, the definition of osteoporosis, and the risk factors for this condition. It is estimated that more than 10 million Americans over the age of 50 have osteoporosis, including 7.8 million women and 2.3 million men. Another 33.6 million people over the age of 50 have low bone mass and thus are at risk for osteoporosis. I believe these numbers are only going to increase as we live longer, so both doctors and patients need to acknowledge the importance of recognizing and treating this disease.
Why Are Calcium and Vitamin D Important?
The first step in preventing and treating osteoporosis is making sure you have an adequate intake of both calcium and vitamin D, which are the building blocks of bones. Bones are living tissues, and are in a constant state of turnover, going through cycles of building bone and breaking down bone. If your diet is deficient in calcium, then your body will take calcium from your bones to keep your blood calcium levels normal.
How Much Calcium and Vitamin D Should I Take?
The Institute of Medicine recommends 1200 mg of calcium (total of diet and supplement) and 600 international units of vitamin D daily, for nonpregnant adults. The National Osteoporosis Foundation and the American Geriatrics Society recommend slightly higher levels of vitamin D, specifically 800 to 1000 IU vitamin D daily for adults older than 65. Unfortunately, most adult general multivitamins do not have more than 400 IU of vitamin D, which is insufficient.
Many physicians including myself feel strongly about the importance of sufficient vitamin D levels and choose to check levels and treat as necessary. However, there is no consensus on the optimal blood level of vitamin D or how much to supplement. If your level is very low, your doctor may prescribe a “mega dose” of 50,000 once weekly. This high dose is not recommended for general use and should only be taken at the direction of your Physician.
What Kind of Vitamin D Should I Take, D2 or D3?
You should not have a problem absorbing vitamin D, so it can be taken as one dose with or without food. The two commonly available forms of vitamin D supplements are vitamin D2(ergocalciferol) and vitamin D3 (cholecalciferol). Some, but not all studies suggest that vitamin D3 increases serum 25(OH)D more efficiently than does vitamin D2. In addition, vitamin D2 is not accurately measured in all vitamin D assays. Therefore, I recommend that you supplement with vitamin D3, when possible, rather than vitamin D2.
Should My Calcium Come From My Diet or Supplements?
I recommend that half of your daily calcium intake should be from dietary sources. Supplements are absorbed as well as dietary calcium, but supplements do have the potential of causing kidney stones and constipation. Additionally, calcium supplements can interfere with the absorption of thyroid hormone, zinc and iron, and as a result, must be taken at a different time of day. Do not take more than 2000 mg of calcium total per day! If you plan to take more than 500 mg of supplemental calcium daily, you must take it in divided doses to optimize absorption. This applies to people taking oral calcium supplements only, because it is difficult to overdose on dietary calcium.
What Are the Top Dietary Sources of Calcium?
The major dietary sources of calcium come from dairy sources- milk, yogurt, hard cheese, ice cream, and cottage cheese, which supply 150-300 mg of calcium per serving. Dark green vegetables, some nuts, breads, and cereals also are good sources of calcium providing up to 100 mg per serving. Lastly, some foods such as cereals and tofu are fortified with up to 1000 mg of calcium per serving. When shopping, I recommend that you read the Nutrition Facts Label and select foods that contain 10 percent or more of the Daily Value for calcium. Foods high in calcium or fortified with calcium may be labeled as “calcium-rich” or “excellent source of calcium.”
What Are My Options for Calcium Supplements?
I find this decision to be the most challenging, especially when you as a patient are presented with innumerable choices of brand and formulation at the drugstore. Choosing a calcium supplement should be based on several different factors. First of all, each supplement has a different amount of elemental calcium, which is the actual amount of calcium that your body absorbs. If your supplement is low in elemental calcium, you may need to take more tablets to get to your daily requirement. Secondly, it depends on which type of calcium supplement you best tolerate. If you are taking other medications, you may not be able to take calcium carbonate. If you suffer from constipation, you may want to also avoid calcium carbonate. Quality and cost are always a factor, and so it is important to confirm that your supplement bears the USP, CL or NSF abbreviation and meets voluntary industry standards for quality, purity, and potency. Lastly, avoid products made from unrefined oyster shell, bone meal, dolomite, or coral, as they may contain lead or other toxic metals.
• Calcium carbonate- 40% elemental calcium; less expensive; best absorbed with meals, poorly absorbed in patients taking PPIs (ie prilosec) or H2 blockers (ie pepcid). Examples: Caltrate, Viactiv Calcium Chews, Os-Cal, GNC Calcium Plus and Tums
• Calcium citrate- 21% elemental calcium; best-absorbed fasting or with a meal, best for those patients on acid reducers. Examples: Citracal and GNC Calcimate Plus 800 with Mag/Vit D, TwinLab Calcium Citrate Caps, Solgar Calcium Citrate
• Calcium gluconate, calcium lactate, and calcium phosphate are not recommended because their levels of elemental calcium are too low
What Increases or Decreases Calcium Absorption?
Vitamin D enhances calcium absorption, so please make sure you get 800 IU of vitamin D3 daily. Be careful of eating foods high in insoluble fiber (such as wheat bran and whole grains) at the same time as your calcium supplement, because these foods can decrease calcium absorption. Phosphoric acid from dark sodas also can interfere with calcium absorption, so do not take calcium with your diet Coke. Trade that soda for water! If you use magnesium-containing laxatives on a regular basis, your calcium absorption will be compromised. It might be a good idea to talk to your doctor about other ways to manage your constipation. Love that cup o’ joe? When it comes to coffee and bone health, there is such a thing as “too much of a good thing”. Caffeine increases calcium loss in the urine, so limit yourself to one to two cups of caffeinated coffee per day.
Are Calcium Supplements Linked to Heart Disease?
As you might have heard, there may be a link between calcium supplements and heart disease. This is a controversial topic and the evidence is mixed. More research is needed before we know the true effect calcium supplements may have on your risk of a heart attack. If you have individual questions about the safety of calcium supplements, please talk with your physician.
If you have not already, tally how much dietary calcium you get on average in one day. Then determine whether your current supplements are adequate or if you need to make a purchase. Maybe start a new habit of daily yogurt with breakfast, or add spinach to your evening meal!
It is so important to be health literate, and as a result, make incremental lifestyle and behavior modifications to live your best life. Please continue to follow our blog for evidence-based, highly curated, wellness information!
Stay tuned for our next post: Osteoporosis: Exercise as Medicine
