What are GOOD BONES?
Good Bones now often brings to mind the HGTV show about renovating older homes with good structure, not a reference to low fracture risk bones. Perhaps part of the current dilemma regarding what builds strong bones is due to equating fracture protection only from higher bone density readings. In Europe, bone structure is also factored in and this gives a better diagnosis of future bone fracture risk rather than just density. Good bones have to exhibit the ability to absorb stress and give or flex a little without breaking. Very high density can actually make certain bones too rigid and lead to a higher fracture risk. The proper marriage of bone structure and bone density together is the true measure of bone health, or Good Bones.
UPDATE: To benefit immediately from new research, limit calcium supplementation to no more than 600mg unless you know your dietary intake amount. The safest total amount with diet and supplement sources added together is between 600 mg to 1000 mg per day. Over 1400 mg total per day potentially increases CVD risk. ref With so many foods fortified with extra calcium, like orange juice and cereals, 600mg may actually be a little high for some.** To be fair, here is another study around the same time that arrived at what appears to be an opposite heading, that higher calcium is protective. BUT, look at the dosages for the higher and the truth is revealed (lower <458 mg/d for men, <417 mg/d for women versus the highest quartile of dietary calcium intake (>762 mg/d for men, >688 mg/d for women). ref Here is another study showing longer term benefits against osteoporosis but not for 3 year fracture prevention. ref (Note that the long term benefits were assumed and not a verified fact using just the measurement of increased bone density at 3 years.)
From the Harvard Medical School newsletter:
Here is a key bone basic from the US Surgeon General's report ref : "The bony skeleton is a remarkable organ that serves both a structural function, providing mobility, support, and protection for the body, and a reservoir function, as the storehouse for essential minerals."
- Copied next is conclusion from the next reference: "Serum potassium content shows a significant positive correlation with BMD, suggesting potassium may be involved in the development of osteoporosis in postmenopausal women." ref Remember that blood level (serum) of calcium is very controlled. Potassium protects calcium in bones. ref
From Harvard Medical website the following is copied due to it's importance:
In particular, these studies suggest that high calcium intake doesn’t actually appear to lower a person’s risk for osteoporosis. For example, in the large Harvard studies of male health professionals and female nurses, individuals who drank one glass of milk (or less) per week were at no greater risk of breaking a hip or forearm than were those who drank two or more glasses per week. (2, 3) When researchers combined the data from the Harvard studies with other large prospective studies, they still found no association between calcium intake and fracture risk. (4) Also, the combined results of randomized trials that compared calcium supplements with a placebo showed that calcium supplements did not protect against fractures of the hip or other bones. Moreover, there was some suggestion that calcium supplements taken without vitamin D might even increase the risk of hip fractures. A 2014 study also showed that higher milk consumption during teenage years was not associated with a lower risk of hip fracture in older adults. (increased in some men) ref
Abstract
There is a consensus that adequate calcium intake during bone development, and possibly in adulthood and senescence, helps to prevent bone resorption and osteoporosis. The uptake of dietary calcium should be sufficient to maintain both normal serum calcium concentrations and parathyroid hormone levels in the low normal range throughout the day, otherwise, increased bone resorption occurs. Calcium intake varies with race and with environmental and dietary conditions. Estimating the appropriate amount of calcium to be added to dietary sources for an optimal supplementation regimen is therefore difficult. Few intervention studies have evaluated the dose-effect relationship for calcium supplementation conclusively. The mechanisms regulating fractional calcium absorption as a function of intake suggest that very high daily doses are probably useless. They may be unsafe in the long term because of the risks of hypercalciuria and kidney stones, and of an imbalance in the ratio of calcium to magnesium. Concomitant supplementation with limited amounts of magnesium may reduce this risk and improve mineralization. Dietary intake is 500-600 mg/day in most studies, making 400 mg/day an appropriate supplementary dose for most premenopausal women (RDA 1000 mg/day). After the menopause and during lactation (RDA 1200-1500 mg/day), 800 mg/day is probably appropriate, particularly if low doses of vitamin D are taken concomitantly. PMID:10417956