Swanson Ultra Ultimate Vitamin C Formula Mineral Ascorbate Complex with Bioflavonoids

Our assessment

The evidence shows that this product provides a form of vitamin C with mineral ascorbates and bioflavonoids, which may be gentler on the stomach than plain ascorbic acid. However, the primary ingredient data available is for calcium, not vitamin C. You should be aware that calcium, a common mineral in mineral ascorbate complexes, has specific benefits and risks [NIH ODS].

How it works

Think of calcium as a structural and signaling mineral — it supports bone mineralization and density, and it also helps your muscles relax and your nerves send signals properly [NIH ODS]. The bioflavonoids in this formula are plant compounds that may support the body's use of vitamin C, though specific data on their effect is not available in the provided information.

Safety profile

FDA received 592059 total adverse event reports across all supplements. For the calcium component specifically: high intakes might increase the risk of heart disease and prostate cancer. High blood and urine levels of calcium can cause poor muscle tone, poor kidney function, low phosphate levels, constipation, nausea, weight loss, extreme tiredness, frequent urination, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS] [FDA data].

Our recommendation

Start with one serving per day as directed on the label. Be aware that calcium can reduce absorption of bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin — take this supplement at least two hours apart from those medications [NIH ODS]. If you have a history of kidney stones, heart disease, or prostate cancer, consult your doctor before using. Data on the specific vitamin C and bioflavonoid dosage is not available in the provided information.

Supplement labels contain several key sections regulated by the FDA:

• Serving Size — The recommended amount per dose. Always check this — some products require multiple capsules per serving.
• Amount Per Serving — Shows the quantity of each nutrient in the product, typically in IU (International Units), mg (milligrams), or mcg (micrograms).
• % Daily Value (%DV) — Indicates how much a nutrient in a serving contributes to a daily diet. 5% DV or less is low; 20% DV or more is high.
• Other Ingredients — Lists inactive ingredients like fillers, binders, and capsule materials (e.g., gelatin, cellulose, magnesium stearate).
• Suggested Use — The manufacturer's recommended directions for taking the supplement, including timing and dosage.

Source: FDA Dietary Supplement Labeling Guide