NOW Magnesium & Calcium
Brand: NOW · Form: TABLET [E0155]
Our assessment
The evidence shows that this product combines two essential minerals, but you need to be careful with dosing. Calcium is a foundational nutrient for bone health, and this supplement can help you meet your needs if your diet is low in dairy or fortified foods. However, the data warns that high calcium intakes from supplements may increase the risk of heart disease and prostate cancer [NIH ODS].
How it works
Think of calcium as a structural builder and signal messenger for your body. It supports bone density and mineral deposition, which is critical for preventing fractures as you age. It also aids neuromuscular relaxation, meaning 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 supplement categories. For calcium specifically, taking too much can lead to serious issues. High levels in your blood and urine may cause 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 [FDA data] [NIH ODS]. Calcium can also reduce the absorption of several medications, including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS]. Data not available for specific report counts for this exact product.
Our recommendation
Start by assessing your total daily calcium intake from food. Most adults need 1,000–1,200 mg per day from all sources. Do not exceed that amount with this supplement, as high intakes carry real risks [NIH ODS]. Take this product with food and separate it from any thyroid or antibiotic medications by at least 2 hours [NIH ODS]. If you have a history of kidney stones or heart disease, speak with your doctor before starting this supplement.
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