NOW Calcium & Magnesium
Brand: NOW · Form: TABLET [E0155]
Our assessment
The evidence shows that NOW Calcium & Magnesium is a foundational supplement for bone health, but it requires careful consideration of dosage and potential medication interactions. Our assessment: for most adults, this product can help you meet your daily calcium needs, but you must be aware of the risks associated with high intakes and the specific absorption issues with other medications [NIH ODS].
How it works
Think of calcium as a structural building block for your bones and a key signaler for your muscles and nerves. This product supports bone mineralization and density, and it promotes neuromuscular relaxation and proper nerve signaling [NIH ODS]. The magnesium in the formula works alongside calcium to support these processes.
Safety profile
Safety data is critical here. The FDA has received a total of 592,059 adverse event reports across all supplements, though specific reports for this product are not listed. High calcium intakes may increase the risk of heart disease and prostate cancer [NIH ODS]. Very high levels can cause poor muscle tone, kidney issues, constipation, nausea, weight loss, extreme tiredness, frequent urination, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS]. You must also be aware that calcium can reduce the absorption of bisphosphonates, tetracycline and fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
Our recommendation: Do not exceed the Tolerable Upper Intake Level for calcium without medical supervision. Take this supplement with food and separate it from any medications listed in the interactions by at least 2-4 hours [NIH ODS]. If you have a history of kidney stones, heart disease, or prostate cancer, consult your doctor before starting. Start with a lower dose to assess your tolerance [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 100.0 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