Vitamin D and serotonin among Fibromyalgia patients.

Vitamin D and serotonin among Fibromyalgia patients.

Clinical association of vitamin D and serotonin levels among patients with fibromyalgia syndrome, was published in the journal Neuropsychiatric Disease and Treatment at the end of May 2019.

This study investigated the relationship between vitamin D and serotonin levels among people with Fibromyalgia (FMS). There were many conclusions made from the research including:

  • indication of an association between FMS and hypertension, with 22.5% of the FMS patients having high blood pressure
  • a clear association between obesity and FMS among the patients.
  • a negative relationship between the serotonin levels and FIQR scores.
  •  improved health of FMS patients is associated with normal serotonin levels.
The primary goal of this study was to evaluate the relationship between vitamin D and serotonin levels and FMS severity.

Methods: Forty participants with fibromyalgia were included in the study.  They were aged 20–60 years and diagnosed with FMS, and selected from a hospital rheumatology clinic.
They had their medical history taken, a physical examination, and laboratory testing in the Rheumatology Department at Al-Ameen Hospital in Taif, Saudi Arabia. 
The revised Fibromyalgia Impact Questionnaire (FIQR) was used to determine the severity of their FMS symptoms.

Results: The results showed that 42.5% of the patients were considered to have mild to moderate fibromyalgia. 
The rest had severe/extreme fibromyalgia. This group was more likely to have lower serotonin levels. The results showed a significant negative relationship between the serotonin levels and FIQR scores (P=0.002). However, no significant correlations were found between the vitamin D levels and FIQR scores (P=0.112).

Serotonin levels in FMS study
 Serotonin level according to the FIQR categories,
it shows a significant negative correlation
between serotonin level and FIQR scores.

Conclusion: The findings of this study show that the improved health of FMS patients is associated with normal serotonin levels.

Serotonin is a neurotransmitter - one of the most important neurotransmitters in humans It is synthesized from the amino acid tryptophan. It has an important role in the brain in physiological responses, such as circadian rhythm, mental processes, mood and cognition.

A decrease in serotonin levels is often found in mood swings, major depression, aggressive behavior, and bipolar disorder.  Many researchers have indicated that FMS is also associated with low serotonin levels.

Vitamin D is an essential vitamin and a deficiency can lead to many musculoskeletal diseases such as osteomalacia, rickets, and osteoporosis. Several studies have linked vitamin D deficiency to FMS. However, studies examining the relationship of vitamin D and serotonin levels in fibromyalgia patients are lacking.

The main goal of this study was to assess the presence of vitamin D deficiency and low serotonin levels among randomly selected FMS patients. They also examined the relationship between vitamin D and serotonin levels and the severity of FMS.
These results support the importance of serotonin medication to improve the symptoms of FMS patients. Given that serotonin levels play a significant role in the FMS diagnosis, doctors should request testing for the serum serotonin level in any patient suspected of having FMS. Finally, increasing the sample size and conducting this study in different regions of Saudi Arabia would be recommended for future studies to enhance our understanding of how serotonin and vitamin D levels influence FMS. Authors of study:  Amin OA, Abouzeid SM, Ali SA, Amin BA, Alswat KA


  1. Thanks for a great post! Good info contained within. Vitamin D (D2 & D3) are one of the few supplements I take that I can really tell a difference with. I am D deficient, so if I go any time without taking my supplements, I can feel the change in my mood. I can definitely see the correlation between the Vitamin D & Seratonin. Thanks for this!! ~Stacey

    1. thanks for letting me know Stacey. Some people really seem to notice the difference and benefit greatly. I have noticed that Vitamin D is recommended for many autoimmune conditions as well. Mood is so important to our wellbeing, don't you think?

  2. Lynne Said7:48 AM

    This makes for really interesting reading. I have consistently had an issue with Vitamin D (I know I'm not in the sunniest part of the world) but it has been a really significant problem dropping way below 'deficient' and had to take extremely strong Vit D supplements (given by doctor) to keep bringing it back up. I never had this problem before so still trying to work it out x Thanks for writing this post. Hope you have a lovely day.

    1. Hi Lynne, hope you are on top of your Vit. D levels now. Apparently there are many reasons why skin doesn't make vitamin D - our skin doesn't make vitamin D when exposed to sunlight as efficiently as when you were young, and our kidneys are less able to convert vitamin D to its active form as we age or get fatter!


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