Daily vitamin supplements are a useful way to ensure that you reach the recommended intakes for essential vitamins and minerals. However, many vitamins do cause side effects, including problems with constipation. If you take a multivitamin, it may take some trial and error to determine which components are producing your side effects.
Iron
Iron in multivitamins or alone is a common cause of constipation. The recommended daily intake of iron is 8 mg for adult men and 18 mg for adult women. During pregnancy, this jumps to 27 mg. Constipation caused by prenatal vitamins containing iron is a common complaint, and the effects are worsened by changing hormone levels.
Vitamin D
Vitamin D is important for bone growth and for the absorption of calcium by the body. In some individuals, vitamin D supplements produce unwanted side effects, including constipation. Muscle aches, loss of appetite, nausea, weakness and weight loss are other reported side effects. Talk to your doctor if you are taking vitamin D in combination with calcium since these may interact.
Calcium
Side effects of calcium supplements include constipation, abdominal pain, gas and bloating. These side effects are more frequent in those consuming calcium carbonate supplements. Switching to a different source of calcium, such as calcium citrate, may alleviate constipation and other side effects.
Treatment
Discuss your vitamin supplement needs with a doctor before making any changes. Mild constipation may resolve within a few days as your body adjusts to a new vitamin. Increasing your consumption of water and high fiber foods may help to reduce your symptoms of constipation. Do not take laxatives or stool softeners unless directed to do so by your doctor.
