Skeleton Pirate

Skeleton Pirate
Artist: LindaB


Have you experienced, or read about, negative, and even dangerous, side effects from Fosamax (alendronate), Boniva (ibandronate), Actonel (risedronate), and other bisphosphonates prescribed for osteoporosis? If you have, then rest assured there is a safe, effective treatment for this condition. Strontium, primarily in the form of strontium citrate, is taken orally once a day.

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Tuesday, February 12, 2013

Vitamin D Supplements and USP Verification

Vitamin D supplement potency varies widely, and the amount of vitamin D in over-the-counter and compounded supplements does not necessarily match the amount listed on the label, according to a research letter published February 11, 2013, in the journal JAMA Internal Medicine.

The analysis showed that the amount of vitamin D in these supplements ranged from 9 percent to 146 percent of the amount listed on the label. Not only was there variation among different brands and manufacturers, but also among different pills from the same bottle. The researchers were surprised by the variation in potency among these vitamin D pills. The greatest concern is that individuals with low levels of vitamin D in their blood and consistently taking a supplement with little vitamin D in it, could face health consequences.

The U.S. Food and Drug Administration (FDA) is considering new safety guidelines for some supplements, but, for the most part, the industry remains unregulated. Some manufacturers participate in a voluntary quality verification program operated by the U.S. Pharmacopeial Convention (USP) — an independent, nonprofit organization that sets public standards for the quality of dietary supplements. In order to receive the USP verification mark, manufacturers' facilities undergo annual good manufacturing-practice audits, and their products are tested for quality, potency and purity. Dr. LeBlanc and her colleagues included one supplement from a USP Verified manufacturer in their sample. They found the amount of vitamin D in pills from that bottle was generally more accurate than the other bottles tested.

"The USP verification mark may give consumers some reassurance that the amount of vitamin D in those pills is close to the amount listed on the label," said Erin S. LeBlanc, MD, MPH, lead author and investigator with the Kaiser Permanente Center for Health Research in Portland, Oregon. "There are not many manufacturers that have the USP mark, but it may be worth the extra effort to look for it."

The researchers tested 55 bottles of over-the-counter vitamin D from 12 different manufacturers. The over-the-counter vitamin D pills used in the analysis were purchased at five different stores in Portland, Oregon. The compounded vitamin D was made by a compounding pharmacy in Portland. The analysis was conducted by Eagle Analytical Services, an independent lab in Houston.

USP Verified Dietary Supplements

Click on the brand names below to see a list of USP Verified products and a list of the retail stores where you can buy the products.

Note: I use Nature Made Multi For Her 50+, a multivitamin that contains 1000 IU vitamin D3. There are also several Nature Made vitamin D supplements: Vitamin D—400 IU, Vitamin D3 1000 IU Softgels, Vitamin D3 2000 IU Softgels, and Vitamin D3 5000 IU Softgels. This brand is carried at several brick-and-mortar stores. I buy mine online at If you use my code, KAP600, at checkout, you and I both get a discount.


Kathy said...

Hi Bone Lady,

Thank you! That's very interesting. Do you happen to know which supplement (with the USP mark) that they discovered had better control over the amount of Vit D contained? I'm also in Portland, OR so presumably it would be easy enough to find in these parts


BoneLady said...


No, I don’t know which supplement with the USP label the researchers of this study tested and found to be accurate. You can find out at the following link after subscribing to the website. To me, any product with USP verification is a cut above the rest. There are only seven brands with this verification, and I provided links to all seven on my post.

You can see the first page of the online paper,” Over-the-Counter and Compounded Vitamin D: Is Potency What We Expect?” by Erin S. LeBlanc, MD, MPH; Nancy Perrin, PhD; Jeffery D. Johnson, PhD; Annie Ballatore, MS; Teresa Hillier MD, MS, at this link but must subscribe for full-text access. JAMA Intern Med. 2013;():1-2. doi:10.1001/jamainternmed.2013.3812.

Wandering Skeleton

Wandering Skeleton
Artist: Joel Hoekstra

Osteoporotic Bone

Osteoporotic Bone

How Strontium Builds Bones

Strontium is a mineral that tends to accumulate in bone. Studies have shown that oral doses of strontium are a safe and effective way to prevent and reverse osteoporosis. Doses of 680 mg per day appear to be optimal. See my "For More Information About Strontium" links section.

Osteoporosis is caused by changes in bone production. In healthy young bones there is a constant cycle of new bone growth and bone removal. With age, more bone is removed and less new bone is produced. The bones become less dense and thus more fragile.

Scientists believe that strontium works in two ways. It may stimulate the replication of pre-osteoblasts, leading to an increase in osteoblasts (cells that build bone). Strontium also directly inhibits the activity of osteoclasts (cells that break down bone). The result is stronger bones.

When taking strontium, be sure to take 1200 mg calcium, 1000 IU vitamin D3, and 500 mg magnesium daily. It is best to take strontium late at night on an empty stomach. Calcium and strontium may compete with each other for absorption if taken together.