For strong bones, teeth and muscles everyone should consider taking vitamin D all year round and particularly in winter. A lack of vitamin D can cause muscle soreness and bone pains. Vitamin D regulates calcium and phosphate which are essential for building strong bones and promoting muscle recovery. The recommended daily intake for vitamin D is 10 micrograms per day. Sometimes the amount of vitamin D is expressed as International Units (IU). 1 microgram of vitamin D is equal