The Downsides of Vitamin D Supplementation in Perimenopause

Vitamin D (which is actually a hormone) plays an important role in the regulation of calcium and phosphorus absorption, and maintenance of healthy bones and teeth in perimenopause.  

It may also provide a protective effect against diseases such as cancer, type 1 diabetes, and multiple sclerosis.

Levels of Vitamin D

Despite all of the benefits of Vitamin D in perimenopause and menopause, more is not better and here are three downsides you need to be aware of, especially if you’re taking high doses.

  1. High levels of Vitamin D can be immunosuppressive. Sustained levels over 70 ng/mL may result in negative impacts on the immune system. The form of Vitamin D we get from food, diet, supplements, and sun exposure is called D3. D3 is converted by the liver into 25-D, which functions as a steroid. 1,25-D, the activated form of Vitamin D, functions as both a steroid and a hormone. Steroids are known immunosuppressants.
  2. Because it’s a hormone, it can have hormonal effects and interact with other sex hormones in the body. It can actually exacerbate hot flashes because it can lower estradiol levels! These swings in estradiol are what cause hot flashes. It also increases sex hormone binding globulin which binds up free molecules of hormones, making less estradiol available for use by the body.
  3. The body uses magnesium to convert Vitamin D into its final form and thus can deplete your stores of magnesium. If you start using or increases dosage of D3 and have surprising symptoms show up (e.g. headache, muscle cramp/spasm, acid reflux, anxiety, trouble sleeping), you may blame the Vitamin D. However, these are symptoms of insufficient magnesium. It is most likely that your magnesium levels has been driven too low (due to usage in the Vitamin D conversion).

[bctt tweet=”Despite all of the benefits of Vitamin D in perimenopause and menopause, more is not better and here are three downsides you need to be aware of, especially if you’re taking high doses. #hormones #hotflashes #immunesystem #magnesiumdeficiency #VitaminDdeficiency” username=”DrAnnaGarrett “]

Most perimenopausal and menopausal women in the US are deficient in Vitamin D because they spend lots of time indoors and wear sunscreen when outside. However, because Vitamin D is fat soluble, it is possible to overdo it. Get levels checked before starting supplements.  

When it comes to Vitamin D levels, “normal” does not necessarily equal optimal. The lower limit of the normal range is usually around 30 ng/mL, but YOU want levels between 50 and 70 ng/mL. A rule of thumb for raising levels is 1000IU/day for every 10 points your level is below the optimal range.

The best way to get Vitamin D is by letting skin convert sunlight to D3. Around 10 minutes of direct exposure without sunscreen is all that is required daily. Even though it’s a short amount of time, that can be pretty challenging for me to schedule between work, gym, and all of my other appointments and commitments. I’m sure I’m not alone in that. I’m also willing to bet I’m not the only one who’s careful about exposing their skin to too much direct sunlight (as a 2-time skin cancer survivor).

If you’re going to supplement, choose a product that contains the D3 form of Vitamin D plus Vitamin K2. This helps bone health as the combo directs calcium to bone and not to your arteries.

Caplets may not dissolve properly resulting in poor absorption. I like the isotonic method of delivery because it’s a liquid and moves quickly into the small intestine for greater absorption. Here’s the product I supplement with.

Other Sources of D

Aside from taking an oral Vitamin D supplement, you can also obtain small amounts of Vitamin D from your diet. Here too, it’s important to realize that not all food sources provide the same kind of Vitamin D. Plant sources provide you with D2. The more beneficial D3 can only be had through animal-based sources such as:

  • Fish, such as salmon, mackerel, tuna, and sardines
  • Egg yolk
  • Raw milk

The Bottom Line

There’s overwhelming evidence that Vitamin D is a key player in your overall health. This is understandable when you consider that it is not “just” a vitamin; it’s actually a neuroregulatory steroid hormone that influences nearly 3,000 different genes in your body. Receptors that respond to the vitamin have been found in almost every type of human cell, from your brain to your bones. Optimizing your Vitamin D levels should be at the top of the list for virtually everyone, regardless of your age, sex, color, or health status.

Dr. Anna Garrett is a menopause expert and Doctor of Pharmacy. She helps women who are struggling with symptoms of perimenopause and menopause find natural hormone balancing solutions so they can rock their mojo through midlife and beyond. Dr. Anna is the author of Perimenopause: The Savvy Sister’s Guide to Hormone Harmony. Order your copy at

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