Osteoporosis Supplements: What Really Works?

Article at-a-glance:

  • People spend $10 billion a year on bone health supplements.
  • But only a fraction of ingredients have ever been shown to acutally reduce fractures.
  • Learn which ingredients actually work to grow stronger bones.

By Dr. John Neustadt

Every year people spend nearly $10 billion one bone and joint dietary supplements. But are they are they really getting their money’s worth? Are they actually protecting their bones are just feeling good because they think they’re doing something positive for their health?

Too often people buy products with ingredients that have not been shown to reduce fractures. By definition, dietary supplements are not approved by the FDA to diagnose, treat or prevent a disease; however, manufacturers of some dietary supplements can make certain claims, as approved by the FDA. For example, labels for calcium supplements can state that calcium “reduces osteoporosis risk.”

But what does the research show? Which ingredients and doses have actually been shown to grow stronger bones and, most importantly, reduce fractures? Well, let’s take a look at some of the most common nutrients found in dietary supplements. I think you may be surprised by how slick marketing claims don’t match up with rigorous science.

Calcium and Vitamin D

When most people think about a dietary supplement for bone health and bone building they automatically think of calcium and vitamin D supplements. The FDA has approved calcium and vitamin D to “reduce osteoporosis risk.”

But does calcium reduce fractures? Several studies have looked at this question.

Secondary prevention of osteoporotic fracture (that is, prevention of another fracture once someone already has sustained one) was assessed in a trial of 5292 people aged 70 years or older (average age, 77 years). Volunteers (85% female) were randomized to receive 1 of 4 protocols: 800 IU vitamin D3, 1000 mg calcium carbonate, 800 IU vitamin D3 plus 1000 mg calcium carbonate, or placebo daily for up to 62 months (median duration, 45 months). In this trial no significant difference in fracture risk was detected between groups.

However, another study noted a 16% reduction in fracture risk (P < .025) over 3 years in 2532 community-dwelling residents (average age, 73 years; 59.8% female) who supplemented with 400 IU vitamin D3 and 1000 mg calcium as calcium carbonate daily. As well, in a randomized, open-label, 2-year sequential follow-up study of 43 healthy adult volunteers (14 men, average age 60.6 years; 29 postmenopausal women, average age 54.1 years), participants followed their usual diet for the first year and then were randomized to receive 500 IU vitamin D3 and 500 mg calcium (form of calcium not reported), or no supplementation, from October to March.3 During these winter months in which volunteers took vitamin D3 and calcium, their lumbar BMD was 0.8% greater than in controls (P=.04), while no significant differences between the groups were noted for femoral-neck BMD.

Bottom line for calcium and vitamin D: The bottom line for these research studies is that calcium supplements and vitamin D3 may reduce fractures by about 16%.

If Taking Calcium, Insist on the Best

When taking calcium supplements, people should take the best forms of calcium. There are two primary forms of calcium supplements that you will see in dietary supplements. One is calcium carbonate. This form of calcium is the form that is most frequently used in clinical research because it is less expensive than other forms and you need fewer capsules to obtain the same doses of calcium. However, it is also the least absorbable form. One molecule of calcium carbonate carries four calcium atoms with it. These atoms of calcium are tightly bound to the carbonate molecule. The calcium must be released from the carbonate to be absorbed by the body. To effectively liberate the calcium you need acid, which is provided for in the stomach.

The problem is that as people age they are at increased risk for decreased stomach acid production, thereby lowering the amount of calcium from calcium carbonate that they can absorb. Many people produce less stomach acid as they age, and it’s been estimated that 10–21% of people sixty to sixty-nine years old, 31% of those seventy to seventy-nine years old, and 37% of those above the age of eighty have low stomach acid or no stomach acid at all, and this rate may be higher in people with autoimmune conditions.

To understand if you might not be producing enough stomach acid, ask yourself the following questions: “Do you feel fuller sooner than you used to and stay full longer than you used to when you eat?” Or, “Do you feel fuller sooner than you used to and stay full longer than you used to when you eat?” If the answer to either of these questions is yes, it may be that you have low stomach acid since decreased stomach acid increases the amount of time food sits in the stomach before passing into the small intestines.

When stomach acid is low, vitamins and minerals may not be efficiently released from the food that contains them. This may result in decreased availability of nutrients for absorption and nutritional deficiencies. People with low stomach acid have been shown to be at increased risk for vitamin and mineral deficiencies.

Symptoms of low stomach acid production include bloating or distension after eating, diarrhea or constipation, flatulence after a meal, hair loss in women, heartburn, indigestion, malaise, and prolonged sense of fullness after eating. Additionally, the risk of hip fracture increases by 22% after one year and nearly 60% after four years in people taking acid-blocking medications as compared to people not taking them. Since that study, additional research has pointed to a link between acid-blocking drugs and increased risk for stomach cancer and dementia.

In contrast to calcium carbonate, calcium citrate is the best absorbed calcium supplement form. It does not require extra stomach acid for absorption, hence you may take it anytime in a day, even on an empty stomach. Calcium citrate though provides less elemental calcium per pill than calcium carbonate, so you may need to take more pills per day to meet your nutritional needs.

It has been estimated that people consume about 800 mg per day of calcium in the diet. Therefore, to get the recommended amount of daily calcium of 1200-1600 mg per day, you should take a highly-absorbable form of calcium, such as calcium citrate, in the amount of about 400-1000 mg daily.

Vitamin K2 (MK4 and MK7)

MK4 and MK7 are two types of vitamin K2 that are commercially available in dietary supplements. However, MK7 has never been shown to reduce fractures. In contrast MK4 has been shown to decrease fractures, and has even been approved by the Ministry of Health in Japan since 1995.

MK4 (45 mg/day taken in divided doses) has been studied in more than 25 clinical trials with over 7,000 people and shown to decrease bone fractures more than 80%. Even at extremely high doses in humans of 135 mg/day of MK4, and 250 mg/kg body weight per day in rats showed that MK4 does not increase the risk for blood clots. MK4 is understood to be safe at all amounts, and effective at promoting bone health and building strong bones when 45 mg are taken in divided doses during the day with calcium and vitamin D.

Bottom line for vitamin K2: Only the MK4 form of vitmain K2, and only in the amount of 45 mg per day taken in divided doses has been shown to reduce fractures–by more than 80%. That’s why Osteo-K and Osteo-K Minis contain 45 mg/day MK4, plus vitamin D and the most absorbable form of calcium.


Boron, a trace mineral needed in only tiny amounts, was first discovered in 1910 as being required for plant development and health. In 1985 researchers discovered that humans also require boron. Some foods are good sources of boron, including pears, prunes, apples, raisins, and tomatoes. Studies have shown that 3 milligrams (mg) of boron daily reduces urinary excretion of calcium and magnesium, especially when dietary magnesium is low. Boron supplementation elevates the serum concentrations of 17 beta estradiol and testosterone, again only when dietary magnesium is low. This suggests that boron may promote bone health. However, there is no evidence that boron in bone health supplements improves bone mineral density, decreases bone loss or decreases fractures.

Bottom line for boron: Boron has never been shown to reduce fractures or improve bone density.


Several rigorous clinical trials have evaluated strontium for its bone building effects. Strontium ranelate (SR) is a form of strontium salt from ranelic acid patented by a French company. SR is the only form of strontium that has ever been studied in clinical trials, and is not available in the US. Strontium citrate is the form of strontium available in osteoporosis supplements in the US and has never been studied in clinical trials for its bone building effects.

SR is approved for osteoporosis treatment in most of Europe but not in the US. Studies in rats concluded that SR does have an affinity for bone, decreases bone loss and can build bones. A laboratory study determined that SR can promote osteoblast production. Clinical trials in have shown that taking 500-2000 mg per day of SR can decrease vertebral fractures by 23% to 49%, as well as increase bone mineral density.

People may want to think twice before taking strontium for several reasons. First, strontium is not approved by the US FDA. Second, strontium is heavier than calcium. As such X-rays from a bone density scan bounce off the strontium to a greater degree than calcium, and change what’s called the “refractive index.” Unless the radiologist understands this and uses a mathematical calculation to correct for this, the bone density scan will be inaccurate. Since radiologists are not taught this in medical school or residency, even if you tell them that you are taking strontium most probably the radiologist will have no idea how to correct for it and provide an accurate result.

Bottom line for strontium: Strontium may improve bone density and has been shown to reduce fracture. However, strontium may reduce calcium absorption. It can also create false bone density test results.


Magnesium may play a role in promoting bone health. However, only one small clinical trial, conducted in 1993, has been published on the effectiveness of magnesium for building bone. This study concluded that taking a few hundred milligrams daily of magnesium (as magnesium hydroxide, one of the least absorbable forms of magnesium) may increase bone mineral density by one to eight percent. However, this evidence is quite weak and no studies have ever shown that taking magnesium reduces fractures in osteoporosis.

Regardless, while about 56% of adults do not consume even the minimum recommended daily allowance of magnesium, a good multiple vitamin should still contain at least 100 mg of magnesium as an amino acid chelate, the most absorbable form of magnesium. Additionally, food rich in magnesium includes bran cereal, shredded wheat, brown rice, almonds (also an excellent source of calcium) and swiss chard. So following a healthy eating plan and taking a high quality multiple vitamin should provide all the magnesium you need.

Bottom line for magnesium: Magnesium has never been shown to reduce fractures. And, in fact, the incredible fracture reduction of great than 80% seen in clinical trials using MK4 (45 mg/day) didn’t use magnesium. Eating more magnesium-rich whole foods and taking a high-quality multiple vitamin and mineral supplement is a great way to get enough magnesium.

Soy Isoflavones

Soy isoflavones refers to multiple naturally-occurring chemicals called phytoestrogens. As the name implies, these molecules have estrogenic activity. Since estrogen supplementation has been approved by the FDA as an osteoporosis treatment approach, soy isoflavones have been studied for their bone building effects. Observational studies and clinical trials have not shown any consistent evidence that soy isoflavones can build stronger bones.

Bottom line for soy isoflavones: Inconsistent evidence for bone-builidng and never been shown to reduce fractures.

Horsetail (Equisetum arvense)

Occasionally you may encounter horsetail (Equisetum arvense) in bone health supplements. This botanical is high in silicon and believed by some to promote bone health. However, there are no clinical trials showing that horsetail improves bone mineral density or decreases fractures.

Bottom line for horsetail (Equisetum arvense): Never been shown to build stronger bones or reduce fractures.

Omega-3 Fatty Acids

Omega-3 fatty acids are polyunsaturated fatty acids that have anti-inflammatory actions and lots of research showing cardiovascular disease benefits. In fact, the American Heart Association (AHA) now recommends people consume 2000 mg daily of combined EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) for heart health. There are some bone building supplements that contain omega-3 fatty acids, but in much lower doses than those recommended for heart health. However, while theoretically plausible, there are no studies showing that omega-3 fatty acids build bone or reduce fractures.

Bottom line for omega-3 fatty acids: Never been shown to grow stronger bones or reduce fractures.

If You Liked This, You Might Also Enjoy

Vitamin K and Fractures

Top Alkaline Foods to Eat & Acid Foods to Avoid

The Osteoporosis Diet

Ames BN. Low micronutrient intake may accelerate the degenerative diseases of aging through allocation of scarce micronutrients by triage. PNAS. 2006;103(47):17589-17594. [Article]

Asakura H, Myou S, Ontachi Y. Vitamin K administration to elderly patients with osteoporosis induces no hemostatic activation, even in those with suspected vitamin K deficiency. Osteoporos Int. 2001;12(12):996-1000. [Article]

Baik HW, Russell RM. Vitamin B12 deficiency in the elderly. Annu Rev Nutr. 1999;19:357-377. [Article]

Caverzasio J. Strontium ranelate promotes osteoblastic cell replication through at least two different mechanisms. Bone. 2008;42(6):1131-1136. [Article]

Cockayne S, Adamson J, Lanham-New S, Shearer MJ, Gilbody S, Torgerson DJ. Vitamin K and the Prevention of Fractures: Systematic Review and Meta-analysis of Randomized Controlled Trials. Arch Intern Med. 2006;166(12):1256-1261. [Article]

Grant AM, Avenell A, Campbell MK, et al. Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium Or vitamin D, RECORD): a randomised placebo-controlled trial. Lancet. 2005;365(9471):1621-1628. [Article]

Hurwitz A, Brady DA, Schaal SE, Samloff IM, Dedon J, Ruhl CE. Gastric acidity in older adults. JAMA. 1997;278(8):659-662. [Article]

Iwamoto I, Kosha S, Noguchi S. A longitudinal study of the effect of vitamin K2 on bone mineral density in postmenopausal women a comparative study with vitamin D3 and estrogen-progestin therapy. Maturitas. 1999;31(2):161-164. [Article]

Kassarjian Z, Russell RM. Hypochlorhydria: A Factor in Nutrition. Annual Review of Nutrition. 1989;9(1):271-285. [Article]

Larsen ER, Mosekilde L, Foldspang A. Vitamin D and Calcium Supplementation Prevents Osteoporotic Fractures in Elderly Community Dwelling Residents: A Pragmatic Population-Based 3-Year Intervention Study. Journal of Bone and Mineral Research. 2004;19(3):370-378. [Article]

Marie PJ, Hott M, Modrowski D, et al. An uncoupling agent containing strontium prevents bone loss by depressing bone resorption and maintaining bone formation in estrogen-deficient rats. J Bone Miner Res. 1993;8(5):607-615. [Article]

Meunier PJ, Roux C, Seeman E, et al. The Effects of Strontium Ranelate on the Risk of Vertebral Fracture in Women with Postmenopausal Osteoporosis. N Engl J Med. 2004;350(5):459-468. [Article]

Meunier PJ, Slosman DO, Delmas PD, et al. Strontium ranelate: dose-dependent effects in established postmenopausal vertebral osteoporosis–a 2-year randomized placebo controlled trial. J Clin Endocrinol Metab. 2002;87(5):2060-2066. [Article]

Prousky JE. Cobalamin deficiency in elderly patients. CMAJ. 2005;172(4):450-a-451. [Article]

Sharp GS. The diagnosis and treatment of achlorhydria; preliminary report of new simplified methods. West J Surg Obstet Gynecol. 1953;61(7):353-360. [Article]

Shiraki M, Shiraki Y, Aoki C, Miura M. Vitamin K2 (Menatetrenone) Effectively Prevents Fractures and Sustains Lumbar Bone Mineral Density in Osteoporosis. Journal of Bone and Mineral Research. 2000;15(3):515-522. [Article]

Sturniolo GC, Montino MC, Rossetto L, et al. Inhibition of gastric acid secretion reduces zinc absorption in man. J Am Coll Nutr. 1991;10(4):372-375. [Article]

Ushiroyama T, Ikeda A, Ueki M. Effect of continuous combined therapy with vitamin K2 and vitamin D3 on bone mineral density and coagulofibrinolysis function in postmenopausal women. Maturitas. 2002;41(3):211-221. [Article]

Wood RJ, Suter PM, Russell RM. Mineral requirements of elderly people. Am J Clin Nutr. 1995;62(3):493-505. [Article]

Yang YX, Lewis JD, Epstein S, Metz DC. Long-term proton pump inhibitor therapy and risk of hip fracture. JAMA. 2006;296(24):2947-2953. [Article]

The Best Botanicals for Prostate Health

The Best Botanicals for Prostate Health

The prostate gland is a walnut-sized gland in men located just behind the bladder. The prostate’s primary function is to produce seminal fluid that nourishes and transports sperm. As men age, their risk for prostate issues increases, which can lead to difficulty peeing, erectile dysfunction, incomplete bladder emptying, and waking up during the night to have to go to the bathroom. Prostate cancer risk also increases as men age. This blog discusses the two most common prostate problems—benign prostatic hyperplasia (BPH) and prostate cancer—to help men understand the warning signs and what their options are.

Boswellia Serrata, New Uses for an Old Plant

Boswellia Serrata, New Uses for an Old Plant

Article at-a-glance: Boswellia serrata possesses supports healthy inflammatory activity, with six potent acids that significantly inhibit pro-inflammatory compounds in the body. The most potent of these acids is thought to be acetyl-11-keto-β-boswellic acid (AKBA)...

Top Tips for Healthy Blood Pressure

Top Tips for Healthy Blood Pressure

Article at-a-glance: Blood viscosity is linked to high blood pressure to autoimmune illnesses, cardiovascular disease, stroke, diabetes, depression and even cancer. Many doctors don’t think of blood viscosity when evaluating patients. It’s likely that many Americans...

Share This