Why Magnesium Matters: FDA Announces New Qualified Health Claim

On January 10, 2022, FDA announced in a letter of enforcement discretion a newly qualified health claim for magnesium and reduced risk of high blood pressure.

Both health claims and qualified health claims characterize the relationship between a substance and a reduction in risk of contracting a particular disease or health-related condition and are reviewed by FDA through a petition process.

Qualified health claims are supported by less evidence than the “significant scientific agreement” standard that governs unqualified health claims. Therefore, qualified health claims require a disclaimer or other qualifying language to avoid misleading consumers as to the strength of the scientific evidence supporting the claim.

In January, the FDA reviewed health claims related to magnesium. A review of multiple studies did show some benefits with respect to hypertension, but the findings were varied. They concluded that there was evidence of potential cardiovascular benefits from magnesium, especially with hypertension. Given this attention, we thought it would be a good time to review what we do know about this important mineral.

Magnesium is an essential mineral and the fourth most abundant mineral in the body.

It is an essential cofactor for over 300 enzymatic systems in the body that regulate biochemical reactions. Some of these include protein synthesis, muscle and nerve function, blood pressure maintenance, bone structure, energy production, memory, and detoxification.

Magnesium is especially important in cardiovascular function. Low levels of magnesium are associated with an increased risk of heart disease. Recent studies suggest that magnesium should be the first-line drug therapy for hypertension.

In 2015 the Food and Drug Administration concluded that Americans were under-consuming magnesium and listed it as a “nutrient of concern.” Turns out over 60% of Americans are deficient in magnesium, and 75% of Americans do not get the recommended RDA intake of magnesium. The recommended RDA in men is 400 mg, and in women is 310 mg. (older adults and athletes may need 20 – 50 mg more). In addition, there are certain lifestyle factors like stress and alcohol intake that can further deplete magnesium levels. Deficiency symptoms include anxiety and agitation, restless legs and muscle cramps, sleep disorders, abnormal heart rhythms, poor nail growth, osteopenia and osteoporosis, headaches, and in rare cases, seizures. Foods high in magnesium include pumpkin seeds, spinach, quinoa, nuts and beans, and chocolate.

Magnesium levels measured in the serum are unreliable as our bodies will maintain the magnesium level in the serum at the expense of other tissues. For example, when magnesium levels are low, our body will deplete stores in the bone to maintain serum levels. A red blood cell measurement is the best way to evaluate true magnesium levels. The normal range is 4.2 to 6.8 mg/dl, but optimal levels are over 5.5 mg/dl.

Given the high use of magnesium in the body, getting this mineral in foods or supplements is important if needed.

Choosing the form of magnesium is important. The correct formulation is key to success. Always choose supplements free of fillers, gluten, dairy, soy, and artificial ingredients.

Magnesium Citrate has higher absorption than other forms of magnesium and is often used to support detoxification and regular bowel movements. It also helps to prevent the crystallization of calcium in the kidney and is used to prevent the formation of stones. This form of magnesium is excellent for individuals with constipation. It is important to titrate it until optimal results are achieved. Start at 100-150 mg doses and go up every three days until bowel movements are regular. For those with kidney stones, a daily dose of 100-200 mg may be enough to aid in prevention.

Magnesium Glycinate is the most highly bioavailable form of magnesium. It is the most soluble, so it does not have a laxative effect like the citrate formulation and thus is not helpful for those with constipation and problems with evacuation. Magnesium glycinate is also very tolerated as it is chelated and less likely to cause GI symptoms. This formulation is optimal for treating or preventing headaches, sleep disturbances, restless legs, and muscle cramps. Doses can be divided into twice a day and should never exceed 600 mg unless recommended by your physician.

Magnesium L-Threonate is a special form of magnesium that can cross the blood-brain barrier. This formulation was found to augment synapse-enhancing memory and learning in rodents. In humans, a clinical trial showed Magnesium L-threonate supported cognitive abilities in older adults. This formulation would be best for those struggling with brain fog, cognitive decline, anxiety, and agitation. Doses for these are variable but should start at 200 mg daily and increase to 200 mg twice daily if tolerated.