Home Tell A Friend   |   Contact Us
Products FAQ Buy Now



Common questions about Os-Cal®

Q: When is the best time to take Os-Cal®?

Q: How much Os-Cal® should I be taking?

Q: Since it is difficult for me to swallow caplets, may I chew my Os-Cal®?

Q: Can Os-Cal® be crushed/cut?

Q: Can it be crushed for a G-Tube?

Q: Can men take Os-Cal®?

Q: Does Os-Cal® help with bone loss and osteoporosis?

Q: If someone is allergic to shellfish (oysters in particular), could
Os-Cal® be used?

Q: Is Os-Cal® constipating?

Q: What should a patient do if Os-Cal® (all variants) is accidentally ingested?

Q: What should a patient do in case of accidental overdose?

Q: Why is it strongly recommended that osteoporosis patients treated with bisphosphates (e.g., Actonel) take calcium supplements?

Q: Will Os-Cal® cause kidney stones?

Q: Can I take Os-Cal® if I am taking any prescription or Over-the-Counter (OTC) medication?

Q: What are the recommended daily intake levels of Calcium? What are the recommended daily intake levels of Vitamin D?

Q: What substances can interfere with calcium absorption?

Q: Do the proteins in dairy foods interfere with absorption of calcium?

Q: Does fiber inhibit calcium absorption?

Q: Does Vitamin C interfere with calcium absorption?

Q: Where is calcium carbonate absorbed and excreted?

Q: Will drinking a glass of wine or beer with dinner when taking Os-Cal® affect the absorbsion?

Q: What information do you have regarding the absorption of calcium with and without food? June 2003. (Medical Marketing Response)

Q: What is the source and amount of calcium found in each caplet?

Q: What is the source of the Oyster Shell Powder used in Os-Cal®?

Q: How is oyster shell powder processed in Os-Cal®?

Q: How does calcium carbonate compare to calcium phosphate?

Q: What is the dissolution of Os-Cal®?

Q: What is elemental calcium?

Q: How long it takes Os-Cal® to take effect and increase the level of calcium in the body?

Q: Is it possible to overdose on calcium while taking Os-Cal®?

Q: What is the Vitamin D compound in the Os-Cal® products (including Os-Cal® Chewable)?

Q: What is the benefit of Vitamin D3 as opposed to any other type of Vitamin D?

Q: What are some food sources of vitamin D?

Q: What is the upper tolerable amount of daily vitamin D intake? If I take 2 or 3 Os-Cal® with vitamin D, will that be too much?

Q: Why does your label state that Os-Cal® Calcium+D3 has "no sugar" when it contains corn syrup solids?

Q: Does Os-Cal® Calcium+D3 contain zinc?

Q: How can you make the claim that Os-Cal® Ultra is beneficial for joint health?

Q: Why is there no magnesium in all Os-Cal® variants except Os-Cal® Ultra? I heard that it is necessary for calcium absorption.

Q: How is Os-Cal® Ultra different from the other Os-Cal® formulations?

Q: Why have the extra vitamins and minerals been added to Os-Cal® Ultra? Is Os-Cal® Ultra better absorbed because of the additives?

Q: If my body can only absorb 500 mg of calcium at one time, why does Os-Cal® Ultra contain 600 mg of elemental calcium?

Q: Can I take Os-Cal® Ultra with my daily multi-vitamin?

Q: Can I take Os-Cal® and Actonel at the same time?

Q: What do the various Os-Cal® products actually look like?

Q: Do the Os-Cal® bottles contain Bisphenol A? (BPA)

Q: Does Os-Cal® contain Arsenic?

Q: What is the source of talc in Os-Cal®?

Q: Why do you use dyes in your Os-Cal®?

Q: Do Os-Cal® calcium supplements contain lead?

Q: Is Os-Cal® water soluble?

Q: Does Os-Cal® contain mercury? (Consumer may be concerned about mercury because the source of calcium is oyster shell)

Q: What is Os-Cal® Extra D3?

Q: Is the calcium in Os-Cal® considered to be "food grade" or "pharmaceutical grade"?

Q: Can I still use my bottle of Os-Cal® if it was not stored at 25°C/77°F?

Q: Can Os-Cal® be stored in the refrigerator?

Q: Who regulates Os-Cal®?

Q: Does Os-Cal® meet USP standards?

Q: Is Os-Cal® available in other countries?

Q: Which Os-Cal® was used in the WHI study?

Q: When is the best time to take Os-Cal®?
A: For the best absorbency of calcium there is a need to space out your calcium caplets throughout the day. Studies have shown that calcium absorption from calcium carbonate, the calcium source in Os-Cal®, is best when taken with meals. Also as a matter of convenience and to establish a regular usage routine, it is advised that Os-Cal® be taken with meals, unless directed otherwise by your own physician.
return to questions

Q: How much Os-Cal® should I be taking?
A: Please consult your doctor for how much Os-Cal® you should be taking. Please read and follow label directions if you use Os-Cal®.
return to questions

Q: Since it is difficult for me to swallow caplets, may I chew my Os-Cal®?
A: Os-Cal® is available in a chewable form that is a good choice for those individuals who have difficulty swallowing caplets. The other types of Os-Cal® (Calcium+D, Extra D3 and Ultra) are not designed to be chewed and should be swallowed ‘as is’ with liquid.
return to questions

Q:Can Os-Cal® be crushed/cut?
A:Yes. The Os-Cal® can be desized accordingly without bearing any negative consequences in terms of calcium absorption or therapeutic value differing from its original size / dimension. We do not recommend chewing the caplets.
return to questions

Q: Can it be crushed for a G-Tube?
A: Os-Cal® is a dietary supplement and should be used in accordance with labeled directions. Consult with your health care provider or pharmacists if you should have any further questions.
return to questions

Q: Can men take Os-Cal®?
A: Yes, men can certainly take Os-Cal®. Approximately 25 million American women suffer from osteoporosis and its potential pain and disfigurement, and another one-third to one-half of post-menopausal women are at risk. Although 80% of those who have osteoporosis are women, men are at risk, too. In fact more than five million American men now suffer from osteoporosis.

We all need our calcium, and it's difficult to get what you need solely from your diet. It is generally recommended that adult men and women need about 1,000 mg. of calcium a day, which would require drinking a little over three 8-ounce glasses of milk. Please ask your doctor about your individual requirements.
return to questions

Q: Does Os-Cal® help with bone loss and osteoporosis?
A: While Os-Cal® cannot restore lost bone, the calcium carbonate in Os-Cal® can help to prevent further bone deterioration. Getting adequate supplies of calcium is one factor in helping with the prevention of osteoporosis; other factors including heredity also play a part.
return to questions

Q: If someone is allergic to shellfish (oysters in particular), could Os-Cal® be used?
A: Generally, when a person is allergic to shellfish, they are allergic to a protein in the fish. The oyster shells contained in Os-Cal® are obtained by dredging only ancient oyster beds in offshore U.S. waters. These fossilized shells haven't had living oysters inside of them for thousands of years, and they are carefully ground to a powder, which is the source of calcium carbonate. The oyster shell powder is combined with pharmaceutical grade ingredients and subjected to rigorous testing for safety and tolerability. This helps make sure that the calcium carbonate is in a form that is readily ingested, disintegrated and metabolized by the human body. Since the source of calcium carbonate for Os-Cal® Calcium+D3 and Os-Cal® Extra D3 Caplets are taken from ancient oyster shell reefs and the shells are washed and oven-dried before being milled to supply the calcium, it is very unlikely that any of the protein allergens would be present.
return to questions

Q: Is Os-Cal® constipating?
A: Os-Cal® contains calcium carbonate. Historically, calcium carbonate products have been suspected of possessing a constipating action. However, despite reports, the belief that calcium carbonate is constipating is yet to be proven with sound research methodology. According to the United States Pharmacopoeia (Advice for Patient, 6th ed., vol. 2), the mild constipating which may accompany calcium-containing products is rarely serious and may resolve as your body adjusts to the product. Nevertheless, if constipation persists or worsens, we recommend seeking the advice of your physician.
return to questions

Q:What should a patient do if Os-Cal® (all variants) is accidentally ingested?
A:Os-Cal® is meant to be ingested. Never attempt to induce vomiting. Consult your health care provider if you have concerns.
return to questions

Q:What should a patient do in case of accidental overdose?
A:Never attempt to induce vomiting. Drink plenty of water and obtain medical advice.
return to questions

Q:Why is it strongly recommended that osteoporosis patients treated with bisphosphates (e.g., Actonel) take calcium supplements?
A:If there is not enough calcium available for new bone remodeling, the body will take it from the existing bone, thus defeating the purpose of the drug. Bisphosphates need to be taken with calcium.
return to questions

Q:Will Os-Cal® cause kidney stones?
A:We have been especially aware of investigations involving the suspected calcium/kidney stone relationship for some time, and we offer the following information for your consideration. The proposed link between kidney stones and calcium ingestion has been the subject of numerous research endeavors over the past several years. Many recent findings report that, quite to the contrary of past assumptions, a diet low in calcium does not reduce the risk of kidney stones. Conversely, it has been demonstrated that a higher dietary calcium intake may actually decrease the incidence of symptomatic stones. The New England Journal of Medicine (March 25, 1993) contained the results of the largest prospective trial thus far published on the dietary calcium/kidney stone issue. The authors of this study concluded that urinary oxalate, rather than urinary calcium, appears to be the more important factor in stone formation. They suggested that calcium may actually have a protective effect by preventing oxalate absorption. It is recommended, however, that those who already suffer from kidney stones or who are prone to the formation of such stones consult with their physicians before considering taking calcium.
return to questions

Q:Can I take Os-Cal® if I am taking any prescription or Over-the-Counter (OTC) medication?
A:Calcium Carbonate, the active ingredient in Os-Cal®, has an excellent safety record, and can be used along with many prescriptions and OTC medications.

However, we recommend consulting your doctor or pharmacist before using Os-Cal® in conjunction with any other medication.
return to questions

Q:What are the recommended daily intake levels of Calcium? What are the recommended daily intake levels of Vitamin D?
A:According to the National Institute of Health, individuals at increased risk for Vitamin D deficiency are:

  • Adults (50 years and over)
  • African Americans and others with darker skin
  • Those with limited sun exposure
  • Those consistently wearing sunscreen SPF 8 or greater

Refer to the easy-to-read chart below to find the recommended levels of both calcium and Vitamin D intake for your age range.
Calcium and Vitamin Requirements*
Age Calcium
(milligrams per day)
Vitamin D
(IU per day)
1 - 3 Years 700 600
4 - 8 Years 1000 600
9 - 13 Years 1300 600
14 - 18 Years 1300 600
19 - 30 Years 1000 600
31 - 50 Years 1000 600
51 - 70 Years (Male) 1000 600
51 - 70 Years (Female) 1200 600
Over 70 Years 1200 800
Source: Calcium and Vitamin D: Important at Every Age (January 2012)
http://www.niams.nih.gov/Health_Info/Bone/Bone_Health/Nutrition/

return to questions

Q:What substances can interfere with calcium absorption?
A:According to the Calcium Information Center (CIC), certain substances in foods such as spinach, rhubarb, whole grains and caffeine-containing drinks are believed to reduce the amount of calcium your body can absorb. In truth, they will have little impact on the calcium supplement or calcium-containing foods eaten at the same time.

A high caffeine intake is thought to increase the amount of calcium excreted in the urine, and high levels of both protein and sodium in the diet are also understood to increase calcium excretion. However, more studies are needed in this area to determine recommended safe levels. Overall excessive amounts of caffeine, protein and salts should probably be avoided.

Aluminum-containing antacids, iron supplements and some prescription medications will interfere with absorption and retention of your calcium supplement and vice versa. Consult your physician or pharmacist about the possibility of such an interaction.
return to questions

Q:Do the proteins in dairy foods interfere with absorption of calcium?
A:Dairy protein does not interfere with calcium absorption. While there have been some reports indicating that calcium is absorbed better on a (very) low-protein diet than on a high-protein diet, the difference is so small that it would not make a meaningful difference.
return to questions

Q:Does fiber inhibit calcium absorption?
A:According to the Calcium Information Center (CIC), "Calcium absorption can be blocked to some degree by meals extremely high in fiber". There is no mention of any particular type of fiber (i.e., soluble, insoluble), nor does it specify an amount in grams. For more information, contact your healthcare professional about this issue. (GSK ended its relationship with the CIC).
return to questions

Q:Does Vitamin C interfere with calcium absorption?
A:There is little in the medical literature that would indicate a problem with Vitamin C and calcium absorption. Most of the data shows no effect, and a few studies indicate that calcium may enhance Vitamin C absorption.

We always refer you to your physician or pharmacist whenever there is a question between possible drug/ supplement interactions.
return to questions

Q:Where is calcium carbonate absorbed and excreted?
A:Calcium carbonate is absorbed in the small intestine. It's excreted into the urine and not metabolized by the liver or the kidney.
return to questions

Q:Will drinking a glass of wine or beer with dinner when taking Os-Cal® affect the absorbsion?
A:We have not seen data that looked at the effect of alcohol on calcium absorption. Os-Cal® should be taken with a meal.
return to questions

Q:What information do you have regarding the absorption of calcium with and without food? June 2003. (Medical Marketing Response)
A:There is data to show that calcium absorption is increased with food.

  • Sheikh, MS, et al. Gastrointestinal absorption of calcium from milk and calcium salts. New England Journal of Medicine (1987). Aug 27, 317 (9): 532-536.
    • This landmark study discovered the inaccuracy in the older testing method that has made calcium citrate appear to be superior.
  • Heaney RP, et al. Absorption of calcium as the carbonate and citrate salts, with some observations on method. Osteoporosis Int, 9(1): 19-23 1999.
    • These two studies stated that calcium citrate absorbed better on an empty stomach also stated that absorption is equal when taken with food.
  • Harvey JA, et al. Superior calcium absorption from calcium citrate than calcium carbonate using external forearm counting. J Am Coll Nutr (1990) Dec;9(6): 583-587.
  • Recker RR. Calcium absorption and achlorhydria. N Engl J Med, 313(2): 70-3 1985 Jul 11
    • Surprise: Solubility in water and stomach acidity have little or no effect on absorption when calcium is taken with food.
  • Heaney RP. Calcium supplements: practical considerations. Osteoporosis Int (1991) Feb;1(2):65-71.
  • Heaney RP, et al. Absorbability of calcium sources: The limited role of solubility. Calcif Tissue Int (1990) May;46(5):300-304.
    • Taking calcium with food improves absorption up to 30 percent.
  • Heaney RP et al. Meal effects on calcium absorption. Am J Cln Nutr, 1989 Feb;49(2):372-376.

return to questions

Q:What is the source and amount of calcium found in each caplet?
A:

Os-Cal®
Ultra
Os-Cal®
Calcium + D3
Os-Cal®
Chewable
Os-Cal®
Extra + D3
Source of
Calcium
Refined calcium carbonate Refined calcium carbonate Refined calcium carbonate Refined calcium carbonate
Amount of
calcium carbonate per caplet
1500 mg 1250 mg 1250 mg 1250 mg
Amount of
elemental calcium per caplet
600 mg 500 mg 500 mg 500 mg
Vitamin D 500 IU 200 IU 600 IU 600 IU

return to questions

Q:What is the source of the Oyster Shell Powder used in Os-Cal®?
A:Oyster Shells are obtained by dredging of only defunct oyster beds in off-shore US waters. The shells are carefully ground to a powder, which is the source of calcium carbonate. The oyster shell powder is combined with pharmaceutical grade ingredients to present the calcium carbonate in a form that is readily ingested, disintegrated and metabolized by the human system.
return to questions

Q:How is oyster shell powder processed in Os-Cal®?
A:Oyster Shells are obtained by dredging of only defunct oyster beds in off-shore US waters (San Francisco Bay, according to William Kooser, 8/22/06). The shells are carefully ground to a powder, which is the source of calcium carbonate. The oyster shell powder is combined with pharmaceutical grade ingredients to present the calcium carbonate in a form that is readily ingested, disintegrated and metabolized by the human system.
return to questions

Q:How does calcium carbonate compare to calcium phosphate?
A:Os-Cal® contains calcium carbonate.

According to the Calcium Information Center (CIC), tribasic calcium phosphate provides 39% elemental calcium (the amount your body is actually able to use). It is an easily dissolved and well absorbed supplement that should not cause gas or constipation. It can be taken anytime. Calcium phosphate is the formulation used in calcium-fortified orange juice, soy milk and rice milk.

Calcium carbonate provides 40% elemental calcium. This means that a product which is 1250 mg. of calcium carbonate yields 500 mg. of elemental calcium. Advantages of calcium carbonate are that it is probably the most cost efficient supplement; it has the highest percentage of elemental calcium and it has a track record of effectiveness. Calcium carbonate is best taken with meals to be properly absorbed.
return to questions

Q:What is the dissolution of Os-Cal®?
A:The USP (United States Pharmacopoeia) has established a dissolution standard for calcium carbonate (which includes Os-Cal®) of at least 75% dissolved in 30 minutes. The mean percent dissolution for Os-Cal® 500 tablets in one experiment was 87.6% in 30 minutes and 95.7% in 60 minutes. Although our product met those standards, many calcium supplements did not. In fact, dissolution and disintegration tests are performed on every batch of Os-Cal® to make sure it meets USP standards.

Many people have contacted us after conducting their own "experiments" with Os-Cal® by dropping the caplets in vinegar solution. Our laboratory advises that acetic acid (which is typically found in vinegar) would not be expected to readily dissolve Os-Cal® caplets. It is difficult to replicate the contents and conditions of the stomach to provide a realistic comparison.
return to questions

Q:What is elemental calcium?
A:All calcium supplements are a compound of calcium with other elements. Elemental calcium is the actual amount of calcium the supplement can deliver.
return to questions

Q:How long it takes Os-Cal® to take effect and increase the level of calcium in the body?
A:While taking Os-Cal® may result in “immediate” calcium absorption, as can be measured within the hours, to measure the effect of intake on calcium balance, much longer time frame is needed (6 month and over). Basically to measure changes in bone density most studies compare 6 month to a year after the initiation of treatment.
return to questions

Q:Is it possible to overdose on calcium while taking Os-Cal®?
A:Please consult your health care provider if you are taking any other medications or supplements when taking Os-Cal®.
return to questions

Q:What is the Vitamin D compound in the Os-Cal® products (including Os-Cal® Chewable)?
A:The Vitamin D compound in Os-Cal® is cholecalciferol (Vitamin D3).
return to questions

Q:What is the benefit of Vitamin D3 as opposed to any other type of Vitamin D?
A:Vitamin D is a fat-soluble vitamin that is naturally present in very few foods, added to others, and available as a dietary supplement. It is also produced when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis.

Dietary supplements typically contain one of two types of Vitamin D: Vitamin D2 or Vitamin D3. The Vitamin D compound in Os-Cal® is cholecalciferol (Vitamin D3).

Vitamin D3 is the type your skin makes when it is exposed to sunlight, and is the form of Vitamin D that your body uses most easily. In fact, Vitamin D3 is up to three times more effective than Vitamin D2. All Os-Cal® products only contain Vitamin D3.

Vitamin D is essential for promoting calcium absorption to enable normal mineralization of bone and bone growth. Without sufficient vitamin D, bones can become thin, brittle, or misshapen. Calcium and Vitamin D help protect older adults from osteoporosis. Additionally, Vitamin D has been in the news in conjunction with helping to protect against several serious health risks.
return to questions

Q:What are some food sources of vitamin D?
A:

  • 1 cup of fortified milk: 100 IUs (2.5 micrograms)
  • 1 egg: 28 IUs (0.7 micrograms)
  • 3 oz of boiled shrimp: 120 IUs (3 micrograms)
  • 1 teaspoon of fortified margarine: 20 IUs (0.5 micrograms)
  • Fortified cereal: varies—please check label

return to questions

Q:What is the upper tolerable amount of daily vitamin D intake? If I take 2 or 3 Os-Cal® with vitamin D, will that be too much?
A:It is generally recognized that the tolerable upper intake of vitamin D from dietary sources and supplements combined is around 2000 IU. Therefore, please reassure consumers that taking two or three of these per day will give them between 800 and 1200 IU per day, well below those upper limits.
return to questions

Q:Why does your label state that Os-Cal® Calcium+D3 has "no sugar" when it contains corn syrup solids?
A:According to the food labeling regulation, sugars that need to be included in the supplement fact box are described in the following manner: "Sugars shall be defined as the sum of all free mono and disaccharides (such as glucose, fructose, lactose, and sucrose). Sugar content shall be expressed to the nearest gram. If a serving (number of caplets per dose) is less than 0.5 grams the amount of sugar can be expressed as zero." Listing of sugar alcohols (i.e., Xylitol) in the supplement facts box is voluntary. The corn syrup solids add a dietarily insignificant amount of sugar.
return to questions

Q:Does Os-Cal® Calcium+D3 contain zinc?
A:Every lot of raw materials that goes into Os-Cal® is analyzed for heavy metal contaminants according to USP standards or FCC (Food Chemicals Codex) requirements. If the raw material does not conform to specifications, it will be rejected. But because the calcium carbonate comes from oyster shells, it may contain trace amounts of various heavy metals found naturally in the environment. Because we don't test for zinc, we cannot say that the product contains no zinc; however, if there is zinc, it would be in trace amounts.
return to questions

Q:How can you make the claim that Os-Cal® Ultra is beneficial for joint health?
A:There are several studies that support the Os-Cal® Ultra claim that Os-Cal® Ultra contains nutrients known to enhance bone and joint health.
return to questions

Q:Why is there no magnesium in all Os-Cal® variants except Os-Cal® Ultra? I heard that it is necessary for calcium absorption.
A:The presence of magnesium is required for the body to maintain adequate amounts of calcium in the blood. However, it is not necessary for the magnesium to be taken with the calcium. It is only essential that magnesium be present in adequate amounts in the body.

Magnesium is found in a variety of foods. Dietary sources that contain high amounts of this mineral include cereal, nuts, beans, avocados and spinach. Adequate levels of magnesium are usually consumed as part of a normal diet. Therefore, magnesium supplementation is usually not necessary.

If there is a question on your individual need for magnesium, it is best to consult with your physician.
return to questions

Q:How is Os-Cal® Ultra different from the other Os-Cal® formulations?
A:Os-Cal® Ultra is the most complete Os-Cal® formula for bone health with Calcium, Vitamin D, Vitamin C, Vitamin E, Magnesium, Manganese, Zinc, Copper and Boron. Each caplet contains 600 mg elemental calcium.
return to questions

Q:Why have the extra vitamins and minerals been added to Os-Cal® Ultra? Is Os-Cal® Ultra better absorbed because of the additives?
A:Vitamins C and E, copper, manganese, boron, zinc and magnesium are all recognized as key to helping to enhance overall bone health, not to assist in absorption Recent research has revealed new information that supports benefits of other nutrients in bone and joint health. Most importantly: For some people, a supplement with calcium alone may not be enough. At GlaxoSmithKline Consumer Healthcare, our researchers considered these facts:

  • Taking supplemental vitamin D increases calcium absorption efficiency.1
  • Antioxidant vitamins C and E help to protect cells and tissue, including collagen. 2,3
  • Vitamins C and E, copper, manganese, boron, zinc, and magnesium are all recognized as key to helping to enhance overall bone health.4
Os-Cal® Ultra does more than provide 600mg of highly absorbable calcium + vitamin D. It provides seven additional vitamins and minerals—including vitamins C and E—antioxidants associated with cartilage preservation. 5, 6 The result is Os-Cal®’s complete formula that helps ensure overall bone and joint health.

REFERENCES
  1. Heany R. et al "Absorbability and Cost-effectiveness in Calcium Supplementation." Journal Amer. College Nutrition. 2002; Vol 20, No. 3, 239-246;
  2. Xu H, Watkins B A, Seifert M F. "Vitamin E Stimulates Trabecular Bond Formation and Alters Epiphyseal Cartilage Morphometry." Calcified Tissue International (1995) 57:293-300.
  3. Clark A G, Rohrbaugh A L, Otterness I, Kraus V B. "The Effects of Ascorbic Acid on Cartilage Metabolism in Guinea Pig Articular Cartilage Explants." Matrix Biology 21 (2002) 175-184
  4. Modern Nutrition in Health and Disease; Matrix Biology; Calcified Tissue International; Bibl Nutr Dieta; Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride.
  5. Xu H, Et al. 293-300;
  6. Hall S L, Greendale G A. "The Relation of Dietary Vitamin C Intake to Bond Mineral Density Results from the PEPI Study." Calcified Tissue International (1998) 63: 183-189.

return to questions

Q:If my body can only absorb 500 mg of calcium at one time, why does Os-Cal® Ultra contain 600 mg of elemental calcium?
A:It’s commonly accepted that the body can fully absorb 500-600 mg of CaCO3 (calcium carbonate) in one dose. Amounts above this level will also be absorbed, but not as completely.
return to questions

Q:Can I take Os-Cal® Ultra with my daily multi-vitamin?
A:Yes, the essential nutrients in Os-Cal® Ultra are not meant to supply the complete RDA of all essential nutrients. Os-Cal® Ultra provides you with the essential nutrients critical for maintaining healthy bones and helping to prevent osteoporosis.
return to questions

Q:Can I take Os-Cal® and Actonel at the same time?
A:Os-Cal® and Actonel must be taken at different times of the day because calcium can interfere with the absorption of Actonel. Actonel must be taken first thing in the morning, 30 minutes before eating or drinking (except water).
Os-Cal® should be taken with food in order to increase absorption.
return to questions

Q:What do the various Os-Cal® products actually look like?
A:

Variant Physical description
Os-Cal® Extra + D3 White, oblong, smooth coated, scored caplets about 3/4" long. Debossed with “OS CAL”
Os-Cal® Ultra Light purple/violet, oblong scored caplets about 3/4" long. Debossed with “OSCAL”
Os-Cal® Calcium + D3 Bright green, oblong, scored caplets about 3/4" long. Debossed with “OS CAL”
Os-Cal® Chewable White, round flat tablets about 5/8” diameter. Debossed with “OS-CAL”

return to questions

Q:Do the Os-Cal® bottles contain Bisphenol A? (BPA)
A:Our Os-Cal® bottles do not contain the Bisphenol A. This is commonly used in PVC bottles. The bottles we use are polypropylene or PET.
return to questions

Q:Does Os-Cal® contain Arsenic?
A:We have analyzed the various Os-Cal® SKUs over the past years to confirm their compliance with California's Proposition 65 regulations. The results of these analyses have indicated that there are very low trace amounts of arsenic in these products at the part per billion range, which is very low and which does not pose a health risk to the consumer. It is important to note that arsenic is ubiquitous in the environment at trace amounts and its presence in oyster shell as well as many other materials is naturally-occurring.
return to questions

Q:What is the source of talc in Os-Cal®?
A:The talc used in Os-Cal® is purified magnesium silicate. Any impurities are removed by mechanical filtration followed by further processing and testing to assure compliance with drug standards. Additionally, there is no evidence linking orally ingested, purified talc to adverse effects. Problems reported relating to talc occur from inhalation or vaginal use of talc containing products.
return to questions

Q:Why do you use dyes in your Os-Cal®?
A:The dyes are used to give Os-Cal® its unique appearance.
return to questions

Q:Do Os-Cal® calcium supplements contain lead?
A:Lead occurs naturally everywhere in our environment. All animal and plant tissues contain small amounts of lead, as does the soil from which plants and plant-derived foods are grown. Consequently, nearly everything that we ingest - including water, cereals, fruits, vegetables and dairy products - contains lead in some small amount. Many calcium supplements with the active ingredient calcium carbonate (the most efficiently absorbed form of calcium), including Os-Cal® are derived from sources where trace amounts of lead occur naturally. Since removing lead entirely is impossible, the goal in producing our product is to refine the calcium carbonate to a level where the lead content is in very trace, and safe, amounts. All of the raw materials that go into the Os-Cal® product are assayed prior to manufacture to insure that the trace levels of lead meet the permissible level established by the United States Pharmacopoeia (USP), the body responsible for determining standards for strength and purity of drugs in the United States. The USP has set the lead tolerance level for calcium carbonate at 3 ppm (parts per million). By employing scrupulous quality control procedures, we ensure that every batch of Os-Cal® falls below the 3 ppm level.

The amount of naturally occurring lead contained in Os-Cal® is negligible and in full compliance with the strict standards set forth by the Federal Government.

The trace amount of naturally occurring lead in Os-Cal® meets the strict California proposition 65 lead limit. If the consumer persists, then provide them with the amount of lead. We provided Consumer Reports with the following data for their article:

Os-Cal® Calcium+D3 (based on testing performed by an independent lab):

  • Naturally occurring lead/caplet: 0.42 mcg
  • Naturally occurring lead/1000 mg calcium: 0.84 mcg
  • Prop 65 lead limit/1000 mg calcium: 4.00 mcg
  • USP lead guideline/day: 7.50 mcg
  • Compliance with prop 65: yes
  • Within USP guidelines: yes
Use this information judiciously! Do not share more than you have to!
return to questions

Q:Is Os-Cal® water soluble?
A:It is not water soluble. It will dissolve completely in a fairly small amount of acid, such as found in the stomach when food—even a little food is consumed. Elderly patients or those with difficulty swallowing are recommended to take the caplet with a large glass of water (8oz) to minimize the risk of choking. Caplets may be broken in half.
return to questions

Q:Does Os-Cal® contain mercury? (Consumer may be concerned about mercury because the source of calcium is oyster shell)
A:We have not formally tested for the potential levels of mercury in Os-Cal®. However, with the extensive knowledge we have with regards to the raw materials used in the current Os-Cal® formulations, the level of mercury would be extremely low and should not pose a potential health concern.

Os-Cal® is derived from very specific oyster beds so the source of the calcium is strictly controlled. The purity of the ingredients used in Os-Cal® is governed by USP standards.
return to questions

Q:What is Os-Cal® Extra D3?
A:Os-Cal® Extra D3 is a 500 mg. Calcium Carbonate caplet that contains 600 IU of vitamin D, which is the highest level of Vitamin D of any Os-Cal® product.
return to questions

Q:Is the calcium in Os-Cal® considered to be "food grade" or "pharmaceutical grade"?
A:The calcium carbonate used in each of the Os-Cal® variants are considered FCC or "Food Grade."
return to questions

Q:Can I still use my bottle of Os-Cal® if it was not stored at 25°C/77°F?
A:GSK has established the expiry term for the product based on storage at 25°C/ 77°F; if the product is not maintained in at this condition then we cannot assure that the product will have 100% of label claim through the expiry period.
return to questions

Q:Can Os-Cal® be stored in the refrigerator?
A:We do not generate stability data for these products at 5C (refrigerated conditions) so we do not have specific or direct information to provide. In order to ensure potency of the product, it should be stored at temperatures as directed on the label.
return to questions

Q:Who regulates Os-Cal®?
A:FDA regulates dietary supplements under the Dietary Supplement Health and Education Act of 1994 (DSHEA).
return to questions

Q:Does Os-Cal® meet USP standards?
A:Regarding Os-Cal®’s dissolution, The USP has established a dissolution standard for calcium carbonate products of at least 75% dissolved in 30 minutes and Os-Cal® consistently meets this standard.
return to questions

Q:Is Os-Cal® available in other countries?
A:GSK Consumer Healthcare has marketing rights for Os-Cal® only in the US.
return to questions

Q:Which Os-Cal® was used in the WHI study?
A:Os-Cal® Calcium+D3.
return to questions



This site is intended for U.S. residents only.
GlaxoSmithKline Privacy Statement
Copyright GSK. All rights reserved.

* These statements have not been evaluated by the Food and Drug Administration. These products are not intended to disgnose, treat, cure or prevent any disease.