omega-3 fatty acids: Unsaturated fatty acids found most commonly in fatty fish such as salmon and sardines. The primary omega-3 is alpha-linolenic acid, which your body converts to hormone-like substances called eicosanoids.

ornithine: One of the amino acids that aids in the production of growth hormone — produced by arginine.

osteoporosis : Severe loss of bone tissue.

oxygen : A colorless odorless gas that is essential for plant and animal respiration.