Vitamins are obtained from the diet but the body’s stores different vitamins in a wide variety of ways.
A primary deficiency occurs when there not enough of the vitamin in food. A secondary deficiency may occur due to an underlying disorder that prevents or limits the absorption or use of the vitamin, such as a “lifestyle factor”. People who eat a varied diet are unlikely to develop a severe primary vitamin deficiency.
Some cases discussed where vitamins may be helpful include:
Women of childbearing age taking a folic acid pill every day.
People who are at increased risk for developing osteoporosis (most older adults) are likely to benefit from a regular vitamin D supplement.
People may need vitamin supplements because they have particular medical conditions that can lead to deficiencies.
People who do not have a regular balanced diet.
Adults of all ages who get very little exposure to sunlight.
There are some people who are born with a genetic condition that interferes with the metabolism of vitamins.
Taking daily vitamins is almost surely not harmful but each person must determine their own vitamin intake as we are not able to make any medical assessment or recommendations.