Join the NBI Loyalty Rewards Program

Bone Health 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 in clinical trials to work.
  • Learn which ingredients actually work to maintain strong bones.

By Dr. John Neustadt

Every year people spend nearly $10 billion on bone health supplements. But are they getting their money’s worth? Too often manufacturers put nutrients in their formulas that haven’t been shown in clinical trials to maintain bone strength and reduce fractures. In this blog, I review the research and discuss which ingredients and doses have been shown in clinical trials to maintain strong bones, promote healthy bone density and–most importantly–reduce fractures.

Calcium and Vitamin D

When most people think bone health supplements they think of calcium and vitamin D. The FDA has even approved the health claim for calcium and vitamin D, “Adequate vitamin D and calcium throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis.”

But do calcium and vitamin D promote healthy bone density and reduce fractures?

One study evaluated 2532 people (average age, 73 years; 59.8% female) who supplemented with 400 IU vitamin D3 and 1000 mg calcium as calcium carbonate daily. They concluded that this combiantion reduced fractures 16%. Another study found that vitamin D3 and calcium may reduce the risk by 18%.

Other researchers studied the ability of calcium and vitamin D3 to promote healthy bone density. In one clinical trial, 43 healthy adult volunteers (14 men, average age 60.6 years; 29 postmenopausal women, average age 54.1 years) looked at the ability of calcium and vimtain D3 to support halthy bone mineral density. Volunteers were randomized to receive 500 IU vitamin D3 and 500 mg calcium (form of calcium not reported), or no supplementation. At the end of the study, those who took the dietary supplements had a lumbar BMD that was significantly greater than in those not taking the supplements.

Which form of calcium is best?

There are two primary forms of calcium in supplements. One is calcium carbonate. This form is most frequently used in clinical research because it’s cheap. However, it’s also the least absorbable form. For your body to absorb the calcium, it break it apart from the carbonate. Doing that requires stomach acid.

But many people produce less stomach acid as they get older. 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- or no-stomach acid. This rate may be even higher in people with autoimmune conditions. This reduces the amount of calcium from calcium carbonate that they can absorb.

In contrast to calcium carbonate, calcium citrate does not require extra stomach acid for absorption. This means it’s more bioavailable and people can take it anytime of the day, even on an empty stomach. In fact, calcium citrate is about 24% more absorbable than calcium carbonate. This is why calcium citrate (and vitamin D3) is in Osteo-K and Osteo-K Minis.

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

Vitamin K2 (MK4 and MK7)

MK4 and MK7 are two types of vitamin K2 that are commercially available in dietary supplements. However, MK4 is the most researched for of vitamin K2 for bone health and the only one with an approved health claim for bone support from the Ministry of Health in Japan. MK4 is also the only form of vitamin K2 shown to not only promote healthy bones, but also support brain, immune and liver health.

The health benefits of MK4 have been researched for more than thirty years. More than 25 clinicals trials with over 7000 volunteers conclude that MK4 (45 mg/day) maintains strong bones. MK4 (45 mg/day taken in divided doses) has been shown to maintain healthy bone mineral density. More imporantly, it’ shown to decrease fractures more than 70%. In contrast, MK7 has not been shown to reduce fractures as the primary endpoint in clinical trials.

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 and effective at promoting bone health and maintaining bone strength 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 vitamin K2, which is in Osteo-K and Osteo-K Minis, and only in the amount of 45 mg per day taken in divided doses has been shown to promote healthy bone density, support bone matrix health and maintain strong bones with a 70% reduction in fractures.


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 boosts bone mineral density or decreases fractures.

However, in clinical trials boron has been shown to support joint health, joint mobility and physical function, which is why it’s in Joint Relief.

Bottom line for boron: Boron has never been shown to reduce fractures or boost 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 bone health supplements in the US and has never been studied in clinical trials for its bone building effects.

SR is approved for osteoporosis 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 support healthy bone density and has been shown to reduce fractures. However, strontium may reduce calcium absorption. It can also create false bone density.


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.

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 more than 70% 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. 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 balance inflammation and support cardiovascular health. 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

  1. Ames BN. 2006;103(47):17589-17594.
  2. Asakura H, Myou S, Ontachi Y. 2001;12(12):996-1000.
  3. Baik HW, Russell RM. 1999;19:357-377.
  4. Bischoff-Ferrari HA, Shao A, Dawson-Hughes B, et. al. 2010;21(7):1121-1132.
  5. Caverzasio J. 2008;42(6):1131-1136.
  6. Cockayne S, Adamson J, Lanham-New S, et. al. 2006;166(12):1256-1261.
  7. Grant AM, Avenell A, Campbell MK, et al. 2005;365(9471):1621-1628.
  8. Huang ZB, Wan SL, Lu YJ, et. al. 2015;26(3):1175-1186.
  9. Hurwitz A, Brady DA, Schaal SE, et. al. 1997;278(8):659-662.
  10. Iwamoto I, Kosha S, Noguchi S. 1999;31(2):161-164.
  11. Kassarjian Z, Russell RM. 1989;9(1):271-285.
  12. Larsen ER, Mosekilde L, Foldspang A. 2004;19(3):370-378.
  13. Marie PJ, Hott M, Modrowski D, et al. 1993;8(5):607-615.
  14. Meunier PJ, Roux C, Seeman E, et al. 2004;350(5):459-468.
  15. Meunier PJ, Slosman DO, Delmas PD, et al. 2002;87(5):2060-2066.
  16. Prousky JE. 2005;172(4):450-a-451.
  17. Sharp GS. 1953;61(7):353-360.
  18. Shiraki M, Shiraki Y, Aoki C, Miura M. 2000;15(3):515-522.
  19. Sturniolo GC, Montino MC, Rossetto L, et al. 1991;10(4):372-375.
  20. Ushiroyama T, Ikeda A, Ueki M. 2002;41(3):211-221.
  21. Wood RJ, Suter PM, Russell RM.1995;62(3):493-505.
  22. Yang YX, Lewis JD, Epstein S, Metz DC. 2006;296(24):2947-2953.

Six Surprising Benefits of Vitamin D

Six Surprising Benefits of Vitamin D

Vitamin D does a whole lot more than support healthy bones. Vitamin D supports brain health, muscle size and strength, heart health, mood, pancreas health and insulin balance. This blog discusses six surprising benefits of vitamin D and six more reasons to make sure you get enough of this powerful nutrient.

Top Nutrients Probiotics Make for You

Top Nutrients Probiotics Make for You

One surprising skill probiotics excel at is manufacturing nutrients, which they then release for us to absorb and use for our own needs. It’s like having a little dietary supplement factory in your gut producing vitamins, antioxidants, amino acids, healthy fats and other nutrients. This helps explain many of the probiotic health benefits researchers have discovered. It’s a true symbiotic relationship, where you give them a home and, in turn, they help you survive. Learn which probiotic species produce different nutrients and how they support optimal health.

Share This