21st Century High Potency Calcium 1000 +D3
Brand: 21st Century · Form: TABLET [E0155]
Our assessment
The evidence shows that 21st Century High Potency Calcium 1000 +D3 is a bone health supplement, but you should understand its risks before using it. Calcium supports bone density and mineral deposition, as well as muscle relaxation and nerve signaling [NIH ODS]. However, the data cautions that high calcium intakes might increase the risk of heart disease and prostate cancer [NIH ODS].
How it works
Think of calcium as a structural building block for your bones and a signal manager for your nerves and muscles. It helps your body maintain strong bones through mineralization and ensures your muscles can relax properly after contracting [NIH ODS]. This supplement also includes vitamin D3 to help your body absorb the calcium, though specific D3 dosage data is not available for this product.
Safety profile
FDA received a total of 592,059 adverse event reports for the general supplement category that includes this product [FDA data]. Specific side effects from high calcium intake include 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 know that calcium can reduce the absorption of medications such as bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
Start by consulting your doctor to check your current calcium intake from food and other supplements. Do not exceed 1,000 mg of supplemental calcium daily without medical supervision due to potential heart and prostate risks [NIH ODS]. Take this supplement separately from any medications listed in the interactions to ensure proper absorption [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | 21st Century |
|---|---|
| Serving Size | |
| Contents | 90.0 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