RESUMEN
Recent experimental studies indicate that nitric oxide (NO) is an important regulator of bone turnover in humans by exerting an anabolic effect on bone cell activity. NO is synthesised from the nonessential amino acid L-arginine. Therefore, a supplementation with oral L-arginine might be highly potent to affect bone cell activity via NO synthesis from L-arginine. In our study we examined the effect of a six months oral supplementation with L-arginine-hydrochloride (18 g) on bone metabolism in 15 healthy postmenopausal women. We analysed nitrogen excretion, markers of bone turnover and calcium concentration. The results show neither a change in serum calcium concentration nor in bone turnover as shown by bone markers. In conclusion, L-arginine-hydrochloride supplementation at that concentration seems to have no effect on bone cell activity in healthy postmenopausal women.