HMB is a muscle-building supplement which, according to some studies, is effective but not so much that healthy young strength athletes derive much benefit from it. However, according to a study paid for by a manufacturer of HMB, the supplement works better the higher the level of vitamin D in users' blood.
Just to be clear: the study published recently in the Journal of Parenteral and Enteral Nutrition was financed by supplements maker Metabolic Technologies. [mtibiotech.com] Nearly all the authors of this study also work for the company. The experiment was designed and the results were interpreted by Steven Nissen, the inventor of HMB, and the CEO of Metabolic Technologies.
In 2009 the researchers published the results of a study in which they gave a few dozen people aged over 70 a supplement containing 2 g HMB, 5 g arginine and 1.5 g lysine, every day for a year. [JPEN J Parenter Enteral Nutr. 2009 Jan-Feb; 33(1): 71-82.] The lean body mass of the subjects increased in that year by 1.2 percent.
HMB [structural formula shown below right] is a metabolite of leucine [structural formula below left]. According to Nissen's research, muscles make more effective use of amino acids if there is a higher concentration of HMB in the body.
There are many studies that show this effect, but most of them were produced by Nissen, and the positive effect they show is pretty modest.
In the publication referred to in this article, the researchers re-examined their data carefully and discovered that HMB became more effective, the more vitamin D the elderly subjects had in their blood.
The figure below shows that HMB, arginine and lysine boosted the strength in the legs of the subjects that had more than 30 nanograms per ml of vitamin D in their blood. The ****tail had no effect in the subjects who had lower levels of vitamin D in their blood.
The vitamin D level had no effect on the increase in lean body mass as a result of the HMB.
"These data support the need for further prospective studies of the synergy between HMB and vitamin D in improving muscle strength and function as loss of muscle function and strength in the elderly has been identified as a primary contributory factor to falls and fractures", the researchers write.
The researchersí cautious tone doesn't rhyme with their behaviour. A year before the study was published, HMB inventor Nissen and four other co-authors filed a patent for muscle-strengthening supplements containing HMB and vitamin D. [United States Patent Application 20100179112]
JPEN J Parenter Enteral Nutr. 2011 Nov;35(6):757-62.