Blood levels of Vitamin D reduced and the risk of hip fracture increased after acute stroke

January 03, 2006

Reduced bone mineral density, altered calcium homeostasis (regulation and equilibrium of calcium levels and function) and increased risk of hip fracture are all seen after a stroke. A deficiency of vitamin D is well documented in long-term stroke survivors. In this study the levels of vitamin D were checked in patients who suffered a first acute stroke (acute means sudden and severe). 44 acute stroke patients had their serum vitamin D levels checked and compared to 96 healthy-elderly subjects. The stroke patients had less vitamin D than the healthy elderly with 77% of the patients falling in the insufficient range. The study was performed at Addenbrooke's Hospital, Cambridge, UK, and is published in the January 2006 issue of Stroke, a journal of the American Heart Association.

Commentary by Jerry Hickey, R.Ph.

Recent research with vitamin D shows that it is low in the elderly with osteoporosis and also in the elderly with hip fractures. Having sufficient vitamin D reduces the risk of falling in the elderly, reduces the risk of osteoporosis, reduces the risk of fracture, and has been shown to improve strength.

Protein supplementation supplying branched chain amino acids may decrease mental fatigue during prolonged exercise

Recently it has been shown that serotonin levels increase in the brain during endurance exercise and this leads to mental fatigue. serotonin is made from the amino acid L-tryptophan. Branched chain amino acids (BCAA) are large neutral amino acids just like L-tryptophan and just like L-tryptophan they enter the brain via the same mechanism and therefore under normal circumstances compete with L-tryptophan for absorption (the BCAA are Leucine, Isoleucine and Valine). During exercise the BCAA are used as fuel by the muscles and are not available to compete with L-tryptophan to decrease its entry into the brain (and this is what contributes to the mental fatigue; the unchecked absorption of l-tryptophan). Oral supplementation with a protein improves BCAA levels and this in turn allows competition with L-tryptophan decreasing its absorption into the brain, decreasing the formation of serotonin and delaying central fatigue. The study was performed at Morton College, Oxford, UK, and the University College of physical Education and Sports, and the Department of Physiology and Pharmacology at the Karolinska Institute, Stockholm, Sweden and is published in the January 2006 issue of the Journal of Nutrition