NOW Calcium & Magnesium
Brand: NOW · Form: TABLET [E0155]
Our assessment
The evidence shows that calcium is a critical mineral for your body, primarily supporting bone health. However, the data also highlights important safety considerations you need to be aware of before supplementing. This product provides a combination of calcium and magnesium, and our assessment is based strictly on the available data for calcium [NIH ODS].
How it works
Calcium works in several key ways. It is essential for bone mineralization, meaning it helps deposit minerals into your bone matrix to maintain density and strength. It also plays a role in neuromuscular relaxation, helping your muscles relax and your nerves signal properly after contraction [NIH ODS].
Safety profile
The FDA has received a total of 592,059 adverse event reports for products in this category, though this number covers all reports for the product line, not just this specific supplement [FDA data]. The data on calcium specifically warns that high intakes might increase the risk of heart disease and prostate cancer. Very high levels of calcium in your blood and urine can cause serious issues including poor muscle tone, poor kidney function, low phosphate levels, constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS].
Our recommendation
Before taking this supplement, you should be aware that calcium can reduce the absorption of several medications, including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS]. We recommend you do not take this supplement without first consulting your healthcare provider, especially if you have a history of kidney stones, heart disease, or take any prescription medications. A balanced diet is often the safest way to meet your calcium needs [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 250.0 Tablet(s) |
| Market Status | Off Market |
How to Read This Label
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