Innerbody Review 2026: Review

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

• Side effects are usually minor and consist of self-limited gastrointestinal symptoms such as gas.

Serious risks

• Probiotic use has been linked to bacteremia, fungemia, and infections that led to severe illness, mostly in severely ill or immunocompromised people.
• Severe or fatal infections have been reported in premature infants given probiotics, and the FDA has warned health care providers.
• In a Boston ICU analysis, 6 of 522 patients given LGG had the ingested LGG found in their blood, versus 2 of 21,652 who did not receive it.
• Possible harms include infections, harmful substances produced by the probiotic microorganisms, and transfer of antibiotic resistance genes.
• Some products have contained microorganisms not listed on the label, which in some instances may pose serious health risks.

Avoid or ask a doctor first if

• For high-risk people such as premature infants or seriously ill hospital patients, the risks of probiotics should be carefully weighed against their benefits.
• For people with compromised immune function or other serious underlying diseases, the WGO advises restricting probiotic use to strains and indications with proven efficacy.
• Consult a health care provider before taking a probiotic supplement, especially with health problems. Anyone with a serious underlying condition should be monitored closely.

Possible side effects

• The most common complaints are diarrhea, nausea, abdominal cramps, and other digestive upset.

Serious risks

• High intakes may raise urinary oxalate and uric acid, which could contribute to kidney stones, especially in people with renal disorders.
• The best evidence that vitamin C contributes to kidney stones is in patients who already have hyperoxaluria.
• In people with hereditary hemochromatosis, long-term high doses could worsen iron overload and cause tissue damage.
• A few in vitro studies suggested that supplemental oral vitamin C, acting as a pro-oxidant, could cause chromosomal or DNA damage and possibly contribute to cancer.
• In postmenopausal women with diabetes in the Iowa Women's Health Study, supplemental vitamin C of at least 300 mg/day was significantly associated with a higher risk of dying from CVD.

Avoid or ask a doctor first if

• People with hereditary hemochromatosis face a concern about iron overload with chronic high doses.
• The upper limits do not apply to people receiving vitamin C as medical treatment, who should be under a physician's care.
• Infants should get vitamin C only from formula and food.

Medication interactions

• Vitamin C supplements may interact with radiation therapy and with medications, including chemotherapy drugs and statins.
• People taking these medications regularly should talk with their health care providers about vitamin C intake.

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.

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.