While vitamins and mineral supplements can be beneficial or therapeutic additions to your diet, some supplements tend to cause constipation. Additionally, some minerals taken for the support of certain conditions may confound the constipation side effect, for example, calcium and iron taken during pregnancy.
Vitamin D3
Consuming the recommended daily intake (RDI) of vitamins has no known side effects. Vitamin D, typically taken in the form D3, is a fat-soluble vitamin. Doses of this type of vitamins that grossly exceed the RDI, however, may be toxic. According to the Office of Dietary Supplements, one of the symptoms of vitamin D toxicity is constipation. For adults ages 19 to 50, RDI for vitamin D3 is 5 mcg, or micrograms. For adults ages 51 to 70, the RDI is 10 mcg. For adults 71 years and older, the RDI is 15 mcg. Vitamin D3 is essential for calcium absorption and is not abundant in many foods. Your doctor should advise your intake above the RDI.
Minerals
Iron and calcium are minerals often supplemented for medical conditions such as anemia and osteoporosis, respectively, and during pregnancy. The hormonal responses to pregnancy tend to cause constipation, as do iron and calcium supplements taken to replace or supplement deficiencies. For pregnant and lactating women, the RDI for calcium is 1,300 mg. For pregnant women, RDI for iron is 27 mg, and 9 mg while lactating. For adolescents ages 14 to 18, RDI for calcium is 1,300 mg. For adults ages 18 to 51, RDI for calcium is 1,000 mg; the amount increases to 1,200 over age 51.
For iron, RDI is 8 mg for adult males and 18 mg for adult females. RDI for iron for women ages 51 and older drops to 8 mg. Your doctor should determine any doses larger than the RDI for both calcium and iron.
B-12 Deficiency
Vitamins B-12 is a water-soluble vitamin, meaning toxicity is extremely unlikely. Deficiency in vitamin B-12 may cause constipation, among other symptoms. Oral supplementation may not be sufficient to counteract B-12 deficiency in individuals with certain metabolic abnormalities. Those with B-12 metabolic impairment may benefit from dissolvable, sublingual B-12 or subcutaneous injections of B-12.
References
- National Institutes of Health: Office of Dietary Supplements: Vitamin D
- National Institutes of Health: Office of Dietary Supplements: Calcium
- National Institutes of Health: Office of Dietary Supplements: Iron
- National Institutes of Health: Office of Dietary Supplements: Vitamin B12
- National Institutes of Health: Office of Dietary Supplements: Vitamin C
