The purpose of a randomized, double-blind, placebo-controlled trial published in the journal Nutrition was to determine the effect of magnesium supplementation on individuals suffering from depression who also had magnesium deficiency.1 Patients were included if they had a depression score of >11 in the Beck Depression Inventory-II, and had a serum magnesium level of <1.8 mg/dL in men and <1.9 mg/dL in women. Individuals were then randomized and given either two 250 mg magnesium oxide tablets per day or placebo for two months.
The Beck Depression Inventory-II was used to measure the depression status which included 21 questions for measuring symptoms of depression (sleep disorders, appetite, self-confidence, hope, sadness). Each of the 21 questions had four options with a scoring system of 0 to 3 for each. A total score was obtained out of the 21 questions, which in total ranged from 0 to 63. A normal score was 0-10; mild depression=11-16; 17-20 requires counseling; 21-30=moderate depression; 31-40=severe depression and 40 or more=very severe depression. Intake of food, macronutrients and magnesium were measured with a 24-hour dietary recall questionnaire.
A total of 53 people met the inclusion criteria and were randomized to either the magnesium or placebo group. The mean age of individuals was 32 years old. Of the 26 participants in the magnesium group, 19 were women and 7 were men. Of the 27 in the placebo group, 20 were women and 7 were men.
The mean Beck score declined significantly in each group after the intervention, although the reduction was greater in the magnesium group compared with the placebo group (-15.65 for magnesium and –10.40 for placebo). Not surprisingly, the mean serum magnesium level increased significantly at the end of the study only in the magnesium group. Patients in both groups had hypomagnesemia at the beginning, and at the end, 88.5% of the magnesium group returned to normal serum levels vs 48.1% for the placebo individuals.
Results from this study were similar to another randomized clinical trial published recently in PLoS ONE demonstrating effectiveness of magnesium supplementation after just two weeks. The researchers conclude that magnesium is effective for adults with mid to moderate depression.2
The role of magnesium in human health is complex and widespread. It is an important co-enzyme for many enzyme systems in the transfer of phosphate and energy metabolism. It has major roles in gene stabilization, DNA replication, protein and nucleic acid synthesis and macronutrient metabolism. It also regulates and transfers some ions and is involved in neuro-transmission and neuroplasticity.
The effect of dietary magnesium has previously been investigated in relation to depression and in the majority of those studies there was a relationship between deficiency and incidence of depression.3 A diet with inadequate sources of dark green leafy vegetables, whole grains and nuts can easily cause hypomagnesemia and is seen in many metabolic diseases. Hypomagnesemia incidence among depressed individuals is estimated to be as high as 13.7%, which is about three times higher than the value in non-depressed individuals.
While I will likely not routinely measure serum levels of magnesium, nor erythrocyte or urine magnesium levels in depressed patients, I will often consider more strongly the use of increased doses of magnesium at 250 mg twice daily in depression patients. It is possible that lower amounts could be used when using magnesium amino acid chelates as the source of magnesium, due to enhanced absorption, rather than the magnesium oxide used in the current study.
Given the safety profile of magnesium and its broad range of positive health effects, it makes sense to recommend this supplement to patients who are experiencing symptoms of depression.
Dr. Tori Hudson directs the curriculum for post-graduate training in women's health at the Institute of Women's Health and Integrative Medicine, and is the director of product research and education for VITANICA. For more information on Dr. Hudson visit http://drtorihudson.com/.