These may lead to increased fracture risk and, subsequently, lower mobility. We know this, but what about what we think we know?
For decades we have been told that if we want strong bones, we need to consume dairy, which has calcium and is fortified with vitamin D.
The data are mixed, but studies indicate that dairy may not be as beneficial as we have been led to believe. Even worse, it may be harmful. What about supplements, instead? Again, the data are mixed, but supplements may not be the answer for those who are not deficient.
Holes in the dairy paradigm
The results of a large, observational, 20-year study of men and women in Sweden showed that milk may be harmful. Comparing those who consumed three or more cups of milk daily to those who consumed less than one, there was a 93 percent increased risk of mortality in women aged 39 to 74.
Increased mortality based on dosage was also indicated. Among men, there was a 3 percent per glass increased risk of death.
Women experienced a small, but significant, increased risk of hip fracture, but no increased risk in overall fracture risk. There was no increased risk of fracture in men, but also no benefit.
Higher levels of biomarkers for oxidative stress and inflammation were found in the urine. The researchers surmise that milk has high levels of D-galactose, a simple sugar that may increase inflammation.
The USDA recommends that, from nine years old through adulthood, we consume up to three servings of dairy per day. The USDA may want to rethink these guidelines.
Prior studies show milk may not be beneficial for preventing osteoporotic fractures. Specifically, in a meta-analysis that used data from the Nurses’ Health Study for women and the Health Professionals Follow-up Study for men, neither men nor women saw any benefit from milk consumption in preventing hip fractures.
Unfortunately, in a meta-analysis involving a group of observational studies, there was no statistically significant improvement in hip fracture risk in those men or women ingesting at least 300 mg of calcium from supplements and/or food on a daily basis.
The researchers did not differentiate the types of foods containing calcium. In a group of randomized controlled trials analyzed in the same study, those taking 800 to 1,600 mg of calcium supplements per day also saw no increased benefit in reducing nonvertebral fractures.
In fact, in four clinical trials the researchers actually saw an increase in hip fractures among those who took calcium supplements.
Vitamin D benefit
Finally, though the data are not always consistent for vitamin D and fracture prevention, it appears it may be valuable.
In a meta-analysis of 11 randomized controlled trials, vitamin D supplementation resulted in fracture reduction. When patients were given a median dose of 800 IUs (ranging from 792 to 2,000 IUs) of vitamin D daily, there was a significant 14 percent reduction in nonvertebral fractures and a 30 percent reduction in hip fractures in those 65 years and over.
However, there was no significant effect with lower levels.
We may need to rethink the milk paradigm. No definitive statement can be made about calcium, although in randomized controlled trials supplementing those without a deficiency, there seemed to be no significant benefit.
In order to get benefit from vitamin D supplementation to prevent fracture, patients may need at least 800 IUs per day.
Remember that studies, though imperfect, are better than tradition alone. Prevention and treatment therefore should be individualized, and deficiency in vitamin D or calcium should usually be treated, of course. Please, talk to your doctor before adding or changing any supplements.