Vitamin D and Endometriosis
Last updated: July 2020
Vitamin D is a fat-soluble vitamin that comes in two main forms:
- D2 (ergocalciferol) that you get through the diet
- D3 (cholecalciferol) is responsible for 95% of vitamin D production, this form you get from sun exposure
Calcium levels in the blood are regulated by vitamin D, which is needed for bone density. It is involved in regulating cell growth and differentiation. Vitamin D is also anti-inflammatory and helps to regulate the immune system.
The role of vitamin D in immune diseases is capturing the attention of researchers and studies have found vitamin D status might influence women’s reproductive health.1 Having adequate vitamin D also may reduce the risk of ovarian cancer.1 Additionally, low vitamin D has been linked to hormonal and metabolic disorders in women with polycystic ovarian syndrome, and is linked to low ovarian reserve in older reproductive aged women.1
Research has have shown that vitamin D may be implicated in a number of diseases including autoimmune diseases, certain cancers, cardiovascular diseases, and some mental health conditions.2
When it comes to endometriosis, studies show that vitamin D may also be involved in the development of endometriosis. Endometriosis is a complex disease, influenced by a range of factors including genetics, hormones, the immune system and environmental factors. Inflammation plays a very important role in the growth of the disease.
A review paper looked many different studies on endometriosis and vitamin D, and confirmed that women with endometriosis have lower vitamin D levels than women without endometriosis.1
How can vitamin D influence endometriosis?
Some studies have found that vitamin D can reduce inflammation, reduce the spread of cells, and reduce the formation of blood vessels to lesions which as a result can control the occurrence and growth of endometriosis.1 These results suggest that vitamin D supplementation may have a positive effect as an adjunctive therapy for endometriosis.
What should you do?
Keep an eye on your vitamin D levels. Research shows that serum vitamin D or 25(OH)D levels should be above 50 nmol/L at the end of winter and 60-70 nmol/L at the end of summer (which allows for seasonal decrease).2 Talk to your doctor about testing your vitamin D levels to ensure they are within an adequate range.
How to increase your vitamin D levels
As majority of vitamin D comes from the sun, it’s important to get adequate skin exposure. A walk with 6-7 minutes mid-morning or mid-afternoon in summer will suffice.2 And in winter, as much bare skin exposed as possible for 7 to 40 minutes at noon in winter on most days, will help maintain adequate vitamin D levels.2 In situations where sun exposure is minimal, vitamin D can be obtained from food and supplementation. For those living with minimal sun exposure, the recommended supplementation is 600IU per day for those aged less than 70 years.2
Vitamin D is fat soluble which means you need to eat it with fat or oil to absorb it. Vitamin D is found naturally in small amounts in a few foods such as wild caught fatty fish (such as tuna, mackerel and salmon), but also fortified foods, liver, and eggs.2 Mushrooms that are exposed to sunlight can also have high levels.
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