Vitamin D is essential in bone repair and maintenance. Vitamin D is instrumental in calcium absorption. In cases of vitamin D deficiency osteoporosis is seen. 50% of adults are vitamin D deficient. Further, many adults who have the following factors are at higher than average risk of vitamin D deficiency:

1) Inadequate vitamin D intake

2) Dark complexion

3) Poor absorption due to bowel, liver or kidney problems.

4) The elderly have lower intake at a time of increased need. Insufficient absorption and inadequate intake are also factors for the elderly. Vitamin D levels can be measured. The average intake requirement of vitamin D by supplementation is 1000-5000 IU for optimal health. Higher doses are needed in cases of more pronounced deficiency.