Reacción a "Reactions to study concluding that vitamin D supplementation does not reduce the risk of bone fracture in healthy adults"

This work is published in the second best journal in its category, according to the international research journal rating standards. Therefore, articles published here go through a tough peer-review process.  

In recent years there has been much scientific discussion about which of the two nutrients, calcium or vitamin D, is more important for bones in adulthood. While the role of calcium is out of question during childhood and adolescence, in adults, its ability to prevent bone fractures is more questionable. Vitamin D is the most effective alternative in this area. In fact, it has even been proposed that the daily recommended intake of vitamin D should be increased. However, so far, research has so far yielded mixed results.  

This paper adds to this controversy by showing that vitamin D supplementation does not protect bones from fracture. In fact, it does not do so in vitamin D-deficient participants either, which is a somewhat unexpected result. The negative results extend even to participants taking calcium supplements, a combination that has shown a positive effect in other studies.  

While it is true that fracture risk is only one of the indicators of bone health, the same authors have previously published that vitamin D supplementation does not improve bone density and structure, nor the risk of falling.  

It should be noted that this work has been carried out in healthy people. Therefore, as the authors themselves indicate, this result cannot be extrapolated to people with bone problems such as osteoporosis or osteomalacia.  

Therefore, it can be said that this study leaves the widespread interest in vitamin D in relation to bone health in healthy adults unfounded. However, it is important to mention that other dietary factors affecting bone, such as protein or phosphorus, are not taken into account here, nor is physical exercise. Perhaps this is the key to interpreting the negative results found in this and previous studies. 

It should be remembered that vitamin D is not only important for bone, but is also involved in other cellular processes, such as muscle function, immune system function, tooth maintenance and cell division. In addition, vitamin D deficiencies have been associated with increased risk of upper respiratory tract infections, autoimmune diseases or allergies, cardiovascular problems and even increased mortality. Lower levels of vitamin D have also been linked to obesity, type 2 diabetes and metabolic syndrome.