Passwell Liquid Gold 1 litre. Liquid Gold is a Calcium and Vitamin D3 supplement to promote healthy egg formation and chick growth in birds. Calcium deficiency is often seen in birds kept on all-seed diets, and in egg-laying females. Key Benefits: Liquid Calcium and Vitamin D3 for strong egg shell and bone growth. Essential minerals magnesium & manganese for egg production. Contains lutein, a natural egg-yolk anti-oxidant. Readily absorbable liquid, administered in water, food or orally.