Natural Factors Calcium & Magnesium Citrate With D3
Brand: Natural Factors · Form: TABLET [E0155] On Market
Our assessment
The evidence shows that this supplement provides two essential minerals and vitamin D3, but you need to be careful about dosing. Calcium and magnesium work together for bone health, and the addition of vitamin D3 helps your body absorb calcium efficiently [NIH ODS].
How it works
Think of the combination as a team effort. Calcium supports bone mineralization and neuromuscular relaxation, while magnesium is involved in over 300 enzymatic reactions in your body. Vitamin D3 acts as a key that unlocks calcium absorption in your gut [NIH ODS].
Safety profile
FDA has received 592,059 total adverse event reports across all supplement categories. For calcium specifically, high intakes may increase risk of heart disease and prostate cancer. High levels in blood and urine can cause poor muscle tone, poor kidney function, constipation, nausea, weight loss, extreme tiredness, frequent urination, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS] [FDA data]. Calcium can also reduce absorption of bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
Start with one tablet daily with food to maximize absorption. Take calcium and magnesium supplements separately from thyroid medication or antibiotics by at least 2 hours. Data not available for specific dose per tablet, so follow the label directions exactly [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | Natural Factors |
|---|---|
| Serving Size | |
| Contents | 180.0 Tablet(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