Ritual Essential for Women Prenatal Multivitamin Review 2026: Worth the Price?

Possible side effects

• Commonly reported side effects of omega-3 supplements are usually mild and include unpleasant taste, bad breath, heartburn, nausea, stomach discomfort, diarrhea, headache, and odoriferous sweat.

Serious risks

• Two large trials found 4 g/day of omega-3 supplements for several years slightly increased atrial fibrillation risk in people with CVD or at high risk of CVD.
• The IOM noted that 900 mg/day EPA plus 600 mg/day DHA or more for several weeks might reduce immune function.
• Doses of 2–15 g/day EPA and/or DHA might increase bleeding time.

Medication interactions

• Omega-3 supplements such as fish oil have the potential to interact with medications.

Possible side effects

• High blood calcium from vitamin D toxicity can lead to nausea, vomiting, muscle weakness, and other symptoms.

Serious risks

• Toxicity can cause high blood and urine calcium. In extreme cases it may lead to kidney failure, soft tissue calcification, heart rhythm problems, and death.
• Toxicity is almost always caused by taking too much vitamin D through supplements.

Avoid or ask a doctor first if

• The source says people on regular medications should talk with their health care providers about vitamin D intake and status.

Medication interactions

• Vitamin D supplements may interact with orlistat, statins, steroids, and thiazide diuretics.
• Taking calcium supplements with vitamin D supplements may raise the risk of certain adverse effects.

Possible side effects

• High-dose iron supplements can cause stomach upset, constipation, nausea, abdominal pain, vomiting, and diarrhea.
• Supplements with 25 mg iron or more can reduce zinc absorption and plasma zinc concentrations.

Serious risks

• Large acute intakes from supplements or medicines can lead to corrosive necrosis of the intestine, which might lead to fluid and blood loss, shock, tissue damage, and organ failure.
• In severe cases, iron overdoses can lead to multisystem organ failure, coma, convulsions, and even death.
• Case reports suggest some people develop more serious gastrointestinal effects, including gastritis and gastric lesions.
• At least 43 U.S. children died between 1983 and 2000 from ingesting high-dose iron supplements.
• Without treatment, people with hereditary hemochromatosis typically develop signs of iron toxicity by their 30s.
• Iron toxicity effects in hemochromatosis can include liver cirrhosis, hepatocellular carcinoma, heart disease, and impaired pancreatic function.

Avoid or ask a doctor first if

• People with hemochromatosis: treatment guidance includes avoiding iron and vitamin C supplements.
• The required FDA label on solid iron supplements says accidental overdose is a leading cause of fatal poisoning in children under 6, and to keep the product out of children's reach.

Medication interactions

• Iron supplements may interact with levodopa and levothyroxine.
• Proton pump inhibitors can potentially reduce iron absorption.

Serious risks

• The Food and Nutrition Board set no upper limit for B12 because its potential for toxicity is low.

Avoid or ask a doctor first if

• People who regularly take certain medications are told to talk with their health care providers about their B12 status.

Medication interactions

• B12 supplements may interact with some medications. Gastric acid inhibitors and metformin may affect B12 levels.
• Several types of medications might adversely affect B12 levels.

Possible side effects

• High iodine intakes can cause goiter, elevated TSH levels, and hypothyroidism, some of the same symptoms as iodine deficiency.

Serious risks

• Iodine-induced hyperthyroidism can result from high iodine intakes, including when iodine is given to treat iodine deficiency.
• Studies have shown that excessive iodine intakes cause thyroiditis and thyroid papillary cancer.
• Acute iodine poisoning is rare and is usually caused by doses of many grams. Symptoms include burning of the mouth, throat, and stomach, fever, abdominal pain, nausea, vomiting, diarrhea, weak pulse, and coma.
• Long-term intakes above the UL increase the risk of adverse health effects.

Avoid or ask a doctor first if

• People with autoimmune thyroid disease or iodine deficiency may have adverse effects at iodine intakes considered safe for the general population.
• The ULs do not apply to people receiving iodine for medical treatment, who should be under a physician's care.

Medication interactions

• Iodine supplements have the potential to interact with several types of medications. People taking these medications on a regular basis should discuss their iodine intakes with their health care providers.

Possible side effects

• High doses from supplements or medications can cause diarrhea, nausea, and abdominal cramping.
• Magnesium carbonate, chloride, gluconate, and oxide are the forms most commonly reported to cause diarrhea.

Serious risks

• Very high doses can lead to magnesium toxicity, with low blood pressure, vomiting, difficulty breathing, irregular heartbeat, cardiac arrest and other signs.
• A few cases of fatal hypermagnesemia have been reported.
• Very large doses of magnesium-containing laxatives and antacids have been associated with magnesium toxicity.
• The risk of toxicity increases with impaired kidney function or kidney failure.

Avoid or ask a doctor first if

• People with impaired kidney function or kidney failure face higher risk of magnesium toxicity.
• People taking medications regularly should discuss their magnesium intake with their health care providers.

Medication interactions

• Magnesium may interact with oral bisphosphonates, tetracyclines, and quinolone antibiotics.
• Some medications, including diuretics and proton pump inhibitors, can affect magnesium status.

Serious risks

• The Food and Nutrition Board reported no adverse effects from vitamin K in food or supplements in humans or animals.

Avoid or ask a doctor first if

• People taking medications regularly should talk with their health care providers about their vitamin K status.

Medication interactions

• Vitamin K can interact with warfarin and other anticoagulants.
• Antibiotics, bile acid sequestrants, and orlistat can have adverse effects on vitamin K levels.

Serious risks

• High biotin intakes, possibly even intakes above the AI, may pose a health risk tied to lab testing.
• Biotin beyond recommended intakes can cause clinically significant falsely high or falsely low lab results, depending on the test.
• In a small study of six healthy adults taking 10 mg/day for 1 week, biotin falsely lowered N-terminal pro-brain natriuretic peptide, which could result in a failure to identify congestive heart failure. Thyroid stimulating hormone was also falsely lowered.
• Case reports describe findings falsely indicating Graves' disease and severe hyperthyroidism in patients taking 10–300 mg biotin per day.
• A single 10 mg dose of biotin has interfered with thyroid function tests given within 24 hours.
• Per FDA, a patient with a high intake of supplemental biotin died after a troponin test gave a falsely low result because of biotin interference.

Medication interactions

• Biotin can interact with certain medications, and some medications can have an adverse effect on biotin levels.

Possible side effects

• Accidental swallowing of boric acid or borax, found in some household cleaners and pesticides, is linked to digestive, skin and nervous system symptoms.
• Boron toxicity can also cause headache, hypothermia, restlessness, and other symptoms.

Serious risks

• Extremely high doses of boron can be fatal in adults.
• In infants, high boron intakes have caused anemia, seizures, erythema, and thin hair.
• The upper limits are based on reproductive and developmental effects seen in animals.

Avoid or ask a doctor first if

• Infants should get boron only from breast milk, formula, and food.

Medication interactions

• Boron is not known to have any clinically relevant interactions with medications.