Multivitamins

Multivitamins are the most popular product for general health as dietary supplements with wide range of choice for selection.  All varieties/brands are clearly labeled with RDI and may also offer special formula for age, gender, and special needs (i.e., pregnancy, pediatric). 

Practical Considerations

• For multivitamin formula with iron, may cause constipation. In addition, recent findings suggest iron may be potentially harmful to human brain and health.
• Multivitamin formulas often contain minerals in small amount; however, additional dose may be needed for deficiency correction.
• When buying once daily formula for large bottle size, pay close attention for expiration or best use by date.
• The chewy gummy Vitamins contain high sugar and diabetic patients should avoid.
• Take the daily dose in the morning shall be better utilized during the day.
  

Calcium/Vitamin D

Calcium and Vitamin D are for strong bones and with other health benefits. They are essential for all ages.

Practical Considerations

• Calcium carbonate and calcium citrate are the two main types of calcium supplements, but they could be equally effective.
• Gas, bloating, and constipation are more common with calcium carbonate, which is also harder to digest.  Take calcium carbonate with food is advised. 
• To retain maximum supplement absorption, take about 500 mg or less at one time
• The chewy gummy calcium contain high sugar and diabetic patients should avoid.
• Overdose may increase risk for kidney stones.
• As your body needs vitamin D to use calcium, it makes sense to select the calcium + Vitamin D formula. Vitamin deficiency is common and asymptomatic; often discovered by lab results.
  

References:
http://www.randomhouse.com/highschool/catalog/display.pperl?isbn=9781101886120&view=print
http://www.health.harvard.edu/staying-healthy/what_you_need_to_know_about_calcium

Resources:

For current product report and review, see
https://labdoor.com/rankings/multivitamins
https://labdoor.com/rankings/calcium