Research shows correlation between low AMH levels and vitamin D - vitamin D levels influence AMH test results.

Low AMH (Anti-Mullerian Hormone) is a sign of diminished ovarian reserve. If you have been tested for AMH and it came back low, you may want to have your vitamin D levels tested as well. A 2012 study in the Journal of Clinical Endocrinology and a 2015 study in Fertility and Sterility found that AMH levels change in relation to vitamin D levels within the body (1,3).

TIP: A low vitamin D level could make AMH appear lower than it really is.

Testing for vitamin D, in general, is a good idea. StatCanada suggests as many as 40% of adults and children are deficient in vitamin D. If there is poor immune function (frequent cold and flus), any neurological condition, autoimmune disease, skin disorder, and fertility concerns, I always recommend running a 25-OH vitamin D blood test. My patients are often surprised when their levels come back out of range or suboptimal. "But I supplement with vitamin D daily!" they cry. 25-OH vitamin D blood range is 75-150 nmol/L. Optimal range is debatable, but I like to see my patients' between 100-125 nmol/L. If AMH is low and FSH is high, consider having your vitamin D blood level checked. Measuring your vitamin D level just makes sense. You can then supplement at an appropriate dose based on your levels to correct or maintain instead of blindly taking, say 2000IU daily because that is "generally recommended for an adult". Having too high of vitamin D levels is also not a great thing, so having your levels tested is also for safety reasons. While vitamin D, even at high doses, is quite safe, it's still possible to get too much of a good thing.

Vitamin D acts more like a hormone and gene regulator that plays a critical role in cellular functioning, making it an important marker to include in a fertility work up.

Vitamin D is a fat soluble nutrient that is made by your skin through sunlight exposure (~20 mins -no sunscreen). Darker skin does not absorb UV rays as easily as lighter skin. People of darker skin are much more likely to have vitamin D deficiency, as are those who are overweight or obese (5). Vitamin D is found in eggs, fatty fish, organic dairy, and organ meats like liver. All of these foods are fertility promoting foods which we now know is no fluke! Vitamin D is also activated in the kidneys, so if you have poor kidney health, get your vitamin D level tested. Other reasons to test for vitamin D are: bone pain, muscle weakness, poor concentration, depression, seasonal affective disorder, frequent colds or flu, any autoimmune disorder, being overweight, being over 35 years of age trying to conceive, or having digestive complaints. Talk to your naturopathic doctor who specializes in fertility about testing your vitamin D and appropriate supplementation as part of your holistic fertility plan.

Tip: Vitamin D3 (not D2) is the active form more usable by the body.  

References:

1. Zaher o. Merhi, et al. Circulating vitamin D correlates to serum anti-mullerian hormone levels in late reproductive-aged women. Association of Reproductive Medicine. Fertil Steril. 2012 Jul; 98(1): 228–234.

2. AMZ Jukic, et al. Association between serum 25 hydroxyvitamin D and ovarian reserve in pre-menopausal women. Journal of North American Menopause Society. 2015 Mar;22(3):312-6.

3. Nicola A. Dennis, et al. The level of serum anti-mullerian hormone correlates with vitamin D status in men and women but not in boys. Journal of Clinical Endocrinology and Metabolism. April 16, 2012.

4. Sarah Abernathy, CH. Study shows correlation between low AMH and vitamin D. Blog post. www.natural-fertility-info.com. Retrieved June 30, 2017.

5. Roberts K, Shields M, Groh M, et al. Overweight and obesity in children and adolescents: Results from the 2009 to 2011 Canadian Health Measures Survey. Health Reports. September 2012;23(3):3-6.