The Surprising Link Between Vitamin D & Pain

Most people, or at least most women of a certain age, know that vitamin D is especially important to us as we get older (women of a certain age, because: increased osteoporosis risk especially for women and especially with untreated menopause, because estrogen and progesterone are also essential for healthy bone turnover*)

^{*Unless you’re a man with typical manly hormones, in which case, testosterone has you covered! But for the rest of us, estrogen and progesterone are what’s needed to avoid the increased risk, and for all of us, vitamin D is necessary to for health bone rebuilding.}

However! While vitamin D is well-known amongst our demographic to be important for bone health (and quite well-known for being relevant to immune health*, too), its effects on some other systems are not so widely understood, and that’s what we’ll talk about today.

^{*See for example: Does Vitamin D Help Against COVID? ← short answer: vitamin D does so many things for your immune system, and/but no, protecting you from COVID is not one of them. However, it may reduce the risk of long COVID, at least.}

First though, a quick vitamin D primer for anyone catching up:

• Vitamin D2 vs Vitamin D3: What You Would Benefit From Knowing
• Vit D + Calcium: Too Much Of A Good Thing? ← this also talks about safe and effective doses, and what goes wrong if you take too much
• How Taking Vitamin D Supplements Can Sabotage Your Vitamin D Levels

So, what’s this about vitamin D and pain?

It’s about how the body responds

Researchers (Dr. Mahdy Abdelhady et al.) investigated this matter and found that women with vitamin D deficiency who underwent surgery were about 3x more likely to experience moderate to severe postoperative pain and used substantially more opioid medication afterwards.

In numbers:

• It was an observational study with 184 women undergoing surgery between September 2024 and April 2025, with half of the participants deficient in vitamin D and half having higher levels.
• Patients with vitamin D levels below 30nmol/L were classified as deficient, while those above that threshold formed the comparison group (we could call it a control group, but since it was an observational study rather than a RCT, we don’t say that).
• Patients with low vitamin D required more fentanyl during* surgery and, on average, used 112 mg more tramadol after surgery through patient-controlled pain pumps.
• None of the patients reported extremely severe pain, but the vitamin D deficient group had many more cases of moderate pain scores between 4 and 6 on a 10-point scale.
• Nausea after surgery was more common in the vitamin D deficient group, and vomiting occurred only in that group, although the vomiting difference wasn’t statistically significant.

^{*Yes, pain relief is needed even while unconscious during general anesthesia, for reasons explained here: How Does Anesthesia Work?}

As for why this happened the way it did: it’s an observational study so we can’t say for 100% sure, but the researchers believe it is likely mostly because of how vitamin D influences pain processing through its effects on inflammation and the immune system, which in turn also affect how the body responds to injury.

You can read this paper in full here: Association between preoperative vitamin D level and postoperative pain in patients undergoing breast cancer surgery: a prospective observational study

Want to learn more?

We’ve written quite a bit about pain management, including:

• Before You Reach For That Tylenol…
• How To Stop Pain Spreading
• How To Dial Down Your Pain
• Managing Chronic Pain (Realistically!)
• Get The Right Help For Your Pain
• The 7 Approaches To Pain Management
• Science-Based Alternative Pain Relief (When Painkillers Aren’t Helping, These Things Might)

Take care!