Solid molybdenum is shown above.
Molybdenum is part of the enzyme xanthine oxidase, which metabolises purines to give uric acid. As yet no effects due to deficiency have been identified, not having any molybdenum may be harmful. The RDA is 45µg for both men and women. The UL for molybdenum is 2mg, at which point too much uric acid is produced. The low solubility of uric acid in aqueous media produces sodium urate crystals around the joints, otherwise known as gout.
Sources of molybdenum are legumes, grain products and nuts.