21st Century 600 Calcium Supplement
Brand: 21st Century · Form: TABLET [E0155]
Our assessment
Our assessment: Calcium is essential for your health, but the evidence shows that supplementation requires careful attention to dosage. The 21st Century 600 Calcium Supplement provides 600 mg of this mineral, which is a significant portion of the daily recommendation. However, we need to be cautious about total intake from all sources [NIH ODS].
How it works
Think of calcium as a structural builder for your bones. It supports bone density and mineral deposition, which is critical for maintaining strong bones as you age. It also plays a key role in neuromuscular relaxation, helping your muscles relax and your nerves signal properly [NIH ODS].
Safety profile
FDA received 592,059 total adverse event reports across all supplement categories. Specific to calcium, some research suggests that high intakes might increase the risk of heart disease and prostate cancer. 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 [FDA data] [NIH ODS]. Calcium can also reduce the absorption of several medications, including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
Our recommendation: Start with this 600 mg supplement only if your diet does not already provide enough calcium. The total daily intake from food and supplements should not exceed safe limits. Take this supplement with food and separate it from any medications you take by at least 2 hours. If you take thyroid medication or antibiotics, consult your doctor before starting [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | 21st Century |
|---|---|
| Serving Size | |
| Contents | 75.0 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