21st Century Calcium Magnesium Zinc + D3
Brand: 21st Century · Form: TABLET [E0155] On Market
Our assessment
The evidence shows that 21st Century Calcium Magnesium Zinc + D3 provides a combination of minerals and vitamin D3 designed to support bone health. Our assessment is that this product can be a useful supplement for filling dietary gaps, but you need to be aware of the specific risks and interactions associated with calcium intake.
How it works
Think of this supplement as a foundation builder. The calcium works on bone mineralization, supporting bone density and mineral deposition, while also aiding in neuromuscular relaxation and nerve signaling [NIH ODS]. The vitamin D3 helps your body absorb that calcium more effectively. Together, these nutrients support the structural integrity of your skeleton.
Safety profile
FDA received a total of 592,059 adverse event reports for this product category. Regarding calcium safety specifically, some research suggests that high calcium intakes might increase the risk of heart disease and prostate cancer [NIH ODS]. High levels of calcium 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]. You should also be aware that calcium can reduce the absorption of several medications, including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
We recommend that you take this supplement with food to improve absorption. To avoid the risks associated with high calcium intake, do not exceed the recommended dose on the label. If you take any of the medications listed in the safety profile, separate your doses by at least two hours. Data not available on the specific amounts of magnesium, zinc, and vitamin D3 in this product. Consult your healthcare provider before starting this supplement, especially if you have a history of kidney stones, heart disease, or take prescription medications.
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | 21st Century |
|---|---|
| Serving Size | |
| Contents | 90.0 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