Lack of blood pressure effect with calcium and magnesium supplementation in adults with high-normal blood pressure. Results from Phase I of the Trials of Hypertension Prevention (TOHP). Trials of Hypertension Prevention (TOHP) Collaborative Research Group
Abstract
Phase I of the Trials of Hypertension Prevention (TOHP) was a randomized, multicenter investigation that included double-blind, placebo-controlled testing of calcium and magnesium supplementation among 698 healthy adults (10.5% blacks and 31% women) aged 30 to 54 years with high-normal diastolic blood pressure (DBP) (80 to 89 mm Hg). Very high compliance (94 to 96% by pill counts) with daily doses of 1 g of calcium (carbonate), 360 mg of magnesium (diglycine), or placebos was corroborated for the active supplements by significant net increases in all urine and serum compliance measures in white men and for urine compliance measures in white women. Overall, neither calcium nor magnesium produced significant changes in blood pressure at 3 and 6 months. Analyses stratified by baseline intakes of calcium, magnesium, sodium, or initial blood pressures also showed no effect of supplementation. These analyses suggested that calcium supplementation may have resulted in a DBP decrease in white women and that response modifiers in this subgroup might have included lower initial urinary calcium levels, urinary sodium levels, or lower body mass index. However, overall analyses indicated that calcium and magnesium supplements are unlikely to lower blood pressure in adults with high-normal DBP. The subgroup analyses, useful to formulate hypotheses, raise the possibility of a benefit to white women, which requires testing in future trials.
How strong is the evidence?
Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 698 participants or records.
Read the paper
Related studies
- Bioactive Molecules Released in Food by Lactic Acid Bacteria: Encrypted Peptides and Biogenic Amines
- A central role for amyloid fibrin microclots in long COVID/PASC: origins and therapeutic implications
- Bioaccessibility and bioavailability of phenolic compounds
- The Glutamate Hypothesis in ALS: Pathophysiology and Drug Development
- Therapeutic Approaches to Genetic Ion Channelopathies and Perspectives in Drug Discovery
- Effects of the Mediterranean Diet on the Components of Metabolic Syndrome Concerning the Cardiometabolic Risk
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.