NOW Magnesium & Calcium
Brand: NOW · Form: TABLET [E0155]
Our assessment
The evidence shows that this combination supplement provides calcium, a mineral critical for bone health. For most adults, the goal is to meet your daily calcium needs through food first, with supplements used to fill any gaps. Data on the specific interactions between calcium and magnesium is not available, but each mineral has a distinct role [NIH ODS].
How it works
Calcium is a structural building block for your bones, supporting bone density and mineral deposition. It also plays a key role in neuromuscular relaxation, helping your muscles relax and your nerves signal properly [NIH ODS].
Safety profile
The FDA has received a total of 592,059 adverse event reports for this product category, though specific side effect counts for this exact combination are not available. For calcium, some research suggests that high intakes might increase the risk of heart disease and prostate cancer. High levels in the blood and urine can 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 [NIH ODS] [FDA data].
Our recommendation
Start by assessing your total daily calcium intake from food and dairy. If you need a supplement, take it with food and separate from medications like bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin by at least 2 hours, as calcium can reduce their absorption [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