No supplement replaces blood pressure medicine or the proven basics. A few have small effects; some popular ones have none, and a couple can be risky.
What studies show
| Supplement | What studies show | Who should be careful |
|---|---|---|
| Vitamin D | No effect on BP in 46 trials | Over 4,000 IU/day can harm |
| Magnesium | Small drop, about 2 points | Kidney disease; some antibiotics |
| Potassium (powders, salt substitutes) | Food potassium lowers BP about 4–5 points | Kidney disease, ACE inhibitors, ARBs, spironolactone |
| Vitamin K2 | No trial shows it clears calcium from arteries | Warfarin users |
| Calcium | Evidence on heart risk is mixed; food sources preferred | Ask your doctor |
| Beetroot juice | Small drop lasting hours | Kidney disease or kidney stones |
What actually works
The AHA lifestyle recommendations describe these effects on blood pressure:
- DASH eating: about 11 mmHg in people with high blood pressure.
- Cutting sodium: about 5–6 mmHg.
- Regular aerobic exercise: about 5–8 mmHg.
- Potassium from food: about 4–5 mmHg.
- Weight loss: about 1 mmHg per kg.
- Less alcohol: about 4 mmHg.
Thinking of trying something?
Tell your doctor or pharmacist. Measure properly for a couple of weeks before and after and compare averages, not one reading. Never stop prescribed medicine on your own.
In-app “Myth or fact?” cards offer short, sourced answers to common blood pressure claims.
Read more about the evidence
- Vitamin D and blood pressure
- Magnesium and blood pressure
- Potassium and blood pressure
- Low-carb diets and blood pressure
- Salt and blood pressure
- Get an accurate blood pressure reading
How FourNumbers helps
FourNumbers can't tell you whether a supplement or diet is right for you — that's for you and your doctor. What it can do is show what's actually happening to your numbers: log readings the right way, keep your medicines and supplements in one list, and bring a report to your doctor.
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Sources
- Beveridge et al., JAMA Internal Medicine 2015
- DAYLIGHT, Hypertension 2015
- Burt et al., JAMA 2019
- NIH ODS: Vitamin D
- 2025 AHA/ACC guideline
- Zhang et al., Hypertension 2016
- NIH ODS: Magnesium
- SSaSS, NEJM 2021
- DASH-Sodium, NEJM 2001
- NIH ODS: Potassium
- FDA: 21 CFR 201.306
- DASH, NEJM 1997
- 2017 ACC/AHA guideline
- Bolland et al., BMJ 2010
- Kopecky et al., Annals of Internal Medicine 2016
Related guides
- Does vitamin D lower blood pressure?
- Does magnesium lower blood pressure?
- Potassium and blood pressure: food, powders and salt substitutes
Last checked: October 2026.