NOW Calcium & Magnesium Citrate Powder with Vitamin D3
Brand: NOW · Form: POWDER [E0162] On Market
Our assessment
The evidence shows that this supplement delivers three key nutrients for bone and muscle health. Our assessment is that it can be a useful option, but you need to be careful with dosing and timing to avoid side effects and interactions [NIH ODS].
How it works
Think of calcium and magnesium as a team for your muscles and bones. Calcium supports bone mineralization and nerve signaling, while magnesium helps with neuromuscular relaxation and energy production [NIH ODS]. Vitamin D3 acts as a master regulator, helping your body absorb calcium efficiently [NIH ODS].
Safety profile
FDA received 592,059 total adverse event reports for supplements in this category. For calcium specifically, high intakes may increase the risk of heart disease and prostate cancer [NIH ODS]. Side effects from excessive calcium include constipation, nausea, weight loss, extreme tiredness, frequent urination, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS].
Our recommendation
Start with a single serving per day. Data not available on exact serving size — follow the product label. Take this supplement with food to improve absorption [NIH ODS]. Separate it from medications like thyroid hormone, antibiotics, and bisphosphonates by at least 2 hours [NIH ODS]. Do not exceed the recommended dose, as high calcium levels can be dangerous [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 8.0 oz. 227.0 Gram(s) |
| Market Status | On 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