Monday, October 28, 2013

High Iron Levels Associated With Accelerated Bone Loss and Fracture Risk

Iron is an essential nutrient and one that is vital for the oxygen-carrying capacity of red blood cells. It is not only important for blood formation, but it is also necessary for optimal bone health. Iron helps convert vitamin D into its active form and therefore is involved in calcium absorption. Iron is also important for normal osteoblastic activity and the formation of strong collagen fibers, the foundation of bone.

Low hemoglobin and iron-deficiency anemia can result from inadequate iron intake; poor absorption due to celiac disease and other GI disorders; or chronic bleeding from excessive menses, ulcers, bleeding hemorrhoids, or cancer. Without iron, or even in low iron anemic states, bone mineral density suffers and fracture risk increases.

On the other end of the spectrum, iron overload can be just as detrimental to a person's health. The two most common causes of iron overload are excessive iron intake (usually from over-supplementing) and hemochromotosis (a hereditary condition where the body absorbs too much iron). Excess iron can deposit within the tissues and organs of the body leading to liver disease, diabetes, heart disease, arthritis, and other maladies. It is also toxic to bone health.

We have known for years that excessive iron loads can have damaging effects to the bone metabolism of animals. But there were no clinical studies to show this effect in humans. Now, for the first time, we have clinical evidence that excessive iron levels can reduce bone density and bone strength in women. In a study by Kim et al. (2013) published in Osteoporosis International, women over the age of 45 with elevated serum ferritin (a blood test for iron levels) were associated with lower bone mineral density and greater risk for fracture. While iron is important for osteoblast function, excessive amounts can be toxic to osteoblasts, reducing their ability to form bone.

It is not unusual for me to see patients with osteoporosis who are consuming excessive amounts of iron. Red meat, liver, fortified cereals, and molasses are all sources high in iron. Take this into consideration if your supplements include iron. Also, while menstruating women may need to supplement with iron to avoid becoming anemic, most postmenopausal women should avoid iron-containing vitamin/mineral supplements.

To avoid inadvertently ingesting too little or too much iron, make sure you are reading labels.      

Kim B.J., S.H. Lee, J.M. Koh, G.S. Kim. 2013. The association between higher serum ferritin level and lower bone mineral density is prominent in women ≥45 years of age (KNHANES 2008-2010). Osteoporosis International 24(10):2627-37.


Monday, October 21, 2013

Calcium Supplements and Cardiovascular Risk

As many of you know, I attended this year's Annual Meeting of the American Society for Bone and Mineral Research in Baltimore (October 4 - 7). While there, I sat in on some fascinating presentations on bone and muscle research--two of them, I thought may be of particularly interesting to you. 

In 2008, a study by Bolland et al. reported a possible association between calcium supplementation and cardiovascular risk. According to Bolland et al. in a 2010 follow-up study, "Calcium supplements (without coadministered vitamin D) are associated with an increased risk of myocardial infarction" The authors further concluded "A reassessment of the role of calcium supplements in the management of osteoporosis is warranted."

Since Bolland's two studies hit the press in 2008 and 2010, there has been considerable controversy over the safety of calcium supplementation as it relates to cardiovascular health. As a result, many people with osteoporosis have, unfortunately, reduced their calcium intake to sub-optimal levels. The two research presentations in Baltimore helped explain our current understanding of this important subject.

The first presentation was by Dr. Douglas Bauer, MD, from the University of California, San Francisco. Dr. Bauer's study assessed calcium intake and the incidence of death in 5967 men over the age of 65 years. The participant's dietary intake of calcium was 1142 ± 590 mg/day, and 65% used calcium supplements. The participants were followed over a 10-year period and those who took in more than 1565 mg/day of calcium had lower mortality than those who took in less than 621 mg/day. The highest rate of death from heart disease was seen in those with the lowest calcium intake (less than 621 mg/day). The authors concluded there was "no evidence that supplements increased the risk of mortality among those with the highest dietary calcium intake." And, "total calcium intake, use of calcium supplements and the combination of high dietary calcium intake and supplement use were not associated with total or cardiovascular mortality."

In the second presentation, Dr. Joshua Lewis, MD, PhD, from the University of Western Australia, Perth, reported on his analysis of 19 randomized controlled trials that studied women over the age of 50 who took calcium supplements. The study encompassed 59,844 participants. The authors concluded "data from this meta-analysis does not support the concept that calcium supplementation with or without vitamin D increase the risk of ischemic heart disease or total mortality in elderly women."  

I hope that the results of these new studies help reduce fears over calcium supplementation. Although these studies conclude that calcium supplementation, even without vitamin D, is not harmful, I still encourage you to maintain optimal vitamin D levels as well as an adequate intake of vitamin K, magnesium, and trace minerals. Vitamins and minerals work synergistically, and to flood the body with calcium without important utilizing factors has the potential to cause metabolic imbalance. So please, I hope you will all continue to take your calcium!

Bolland M.J., P.A. Barber, R.N. Doughty, et al. 2008. Vascular events in healthy older women receiving calcium supplementation: randomized controlled trial. BMJ Feb 2;336(7638):262-6.

Bolland M.J., A. Avenell, J.A. Baron, et al. 2010. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta analysis. BMJ 341:c3691.

Bauer D., S. Harrison, P. Cawthon, et al. 2013. Dietary and supplemental calcium intake and the risk of mortality in older men: the MrOS Study. 35th Annual Meeting of the ASBMR. Abstracts, 1001, pS1.

Lewis J., L. Rejnmark, K. Ivey, et al. 2013. The cardiovascular safety of calcium supplements with or without vitamin D in elderly women: A collaborative meta-analysis of published and unpublished trial level evidence from randomized controlled trials. 35th Annual Meeting of the ASBMR. Abstracts, 1002, p S1. 

Wednesday, October 16, 2013

Radio Show: Osteoporosis: Silent, Searing and Bone Breaking


Aches and Gains with Dr. Paul Christo will feature the following shows this Saturday on Sirius XM Radio- Family Talk 131 (www.siriusxm.com/familytalk) from 8-9 am Eastern time. Podcasts accessible after the shows air on www.paulchristomd.com

Follow Dr. Christo on Twitter or Facebook  for more information on cutting edge pain treatments, and success stories from those who have found relief.


Osteoporosis: Silent, Searing and Bone Breaking
Air Date October 19, 2013,
8:00 am EST

Osteoporosis occurs when the creation of new bone isn’t able to keep up with the removal of old bone.  Bones then become weak, brittle, and painful — so brittle that a fall or even mild stresses like bending over or coughing can cause what is known as a “fragility fracture.”  Our guest is Dr. Keith McCormick. He’s the author of The Whole-Body Approach to Osteoporosis and shares his experience as both a patient who overcame 12 fragility fractures, and an osteoporosis expert who’s developed a nutrition based prevention and treatment program.  

Tuesday, October 8, 2013

ASBMR Annual Meeting

I just returned from the Annual Meeting of the American Society for Bone and Mineral Research (ASBMR) held in Baltimore, MD. While there, I had the opportunity to meet lots of great researchers and doctors who specialize in osteoporosis plus sit in on lectures--all of which were absolutely packed with the latest discoveries in osteoporosis research and therapy.

On my first day in Baltimore I attended a course on densitometry and the diagnosis and management of osteoporosis that was sponsored by the International Society for Clinical Densitometry. I had attended one of their courses about 10 years ago but decided to take it again as a refresher. Although helpful, it also sadly reminded me that bone density testing is not as accurate as one might think.

The next day was all about the interconnectedness of muscle and bone. The ASBMR sponsored a full day symposium entitled Cutting Edge Discoveries in Muscle Biology, Disease and Therapeutics. I was absolutely riveted by some of the lectures. We saw video footage of muscle stem cells (called satellite cells), heard about new discoveries in mitochondrial bioenergetics and why this is so important to bone health, learned about myokines (muscle signaling molecules) that "talk" to bone, and honed in on the connection between sarcopenia (muscle wasting) and bone loss.

The next three days were spent at the ASBMR Annual Meeting proper. Not only did I get to listen, 8 to 5, to fascinating lectures but also viewed hundreds of posters and spoke with many of the lead researchers in these projects. I was absolutely blown away to hear things like:

- Vitamin D is not only important for ensuring gut absorption of calcium, enhancing immunological function, and promoting muscle strength through its direct action on bone--but vitamin D also improves neuromusclular function through its effects on the brain's central nervous system.

- There is a huge problem in our current ability to assess patient's vitamin D levels. Not only are assays commonly off by 15 to 20% (or more), but there is no industry standardization in the assessment or reporting of vitamin D levels. Also, for anyone taking vitamin D2, there is a huge variability of ingested vitamin D2 recovery. This means that any immunoassay testing (rather than HPLC/Tandem MS testing) of these patient's vitamin D levels will yield totally innacurate, and therefore useless, results.

- Bone mineral density examinations (DXAs) are absolutely fraught with potential errors not only by the technician performing the scan but also by the radiologist doing the reading and evaluation. It can be very helpful to know a scanning facility's "precision error" and also the date that it was last measured. The only way to determine "least significant change" (LSC) (the amount of change in bone density that is necessary to know that the change in density from one scan to the next is real) is by knowing a facility's precision error assessment. The bottom line is that you can't take DXA T scores at face value. You need to have the report evaluated by someone familiar with all the possible pitfalls in bone density measuring and reporting.

It was a very fruitful five days!
   
Website design and website development by Confluent Forms LLC, Easthampton MA