NOW Red Mineral Algae

Our assessment

The evidence shows that the primary active ingredient in NOW Red Mineral Algae is calcium, a mineral essential for bone health. Our assessment is that this product can be an effective calcium supplement, but you need to be aware of the specific dosages and potential risks. Data on the exact calcium content per serving for this specific product is not available, so you must check the label carefully before use [NIH ODS].

How it works

Think of calcium as the structural building block for your bones and teeth. It supports bone mineralization and density, acting as a key player in your body's framework. Beyond your skeleton, calcium is critical for neuromuscular relaxation — it helps your muscles relax and your nerves send signals properly [NIH ODS].

Safety profile

FDA received a total of 592,059 adverse event reports across all supplements, though specific numbers for this product are not available. High levels of calcium in the blood and urine can cause side effects including constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, abnormal heart rhythms, and a high risk of death from heart disease [FDA data] [NIH ODS]. Some research also suggests that high calcium intakes might increase the risk of heart disease and prostate cancer [NIH ODS].

Our recommendation

Start by reading the label to determine the exact amount of calcium per serving. Be mindful of your total daily calcium intake from all sources — including food and other supplements — to avoid exceeding safe levels. If you take prescription medications such as bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, or phenytoin, take this supplement at a different time of day to avoid reducing their absorption [NIH ODS].

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