.png)
Vitamin D Deficiency - Why You Need To Test Your Levels Now
Feeling low, tired or run down? A naturopath explains the signs of vitamin D deficiency, the benefits of optimal levels and why testing yours matters now.
Written and medically reviewed by Dr. Courtney Ranieri, ND, a licensed naturopathic doctor registered with the College of Naturopaths of Ontario (Reg. #3726). Last reviewed July 2026.
What's the deal with Vitamin D?
I've been seeing a lot of Vitamin D deficiency in patient bloodwork recently. Vitamin D is also known as the "sunshine vitamin" because it's produced by your skin in response to sunlight. With less sunlight, less time outdoors, and very few foods naturally high in vitamin D, your risk of deficiency increases in the winter months.
7 Signs of Vitamin D Deficiency
- Low energy
- Low mood and anxiety
- Hormonal imbalances
- Muscle weakness or chronic pain
- Decreased libido or testosterone
- Poor sleep
- Infertility (there's emerging research on the importance of Vitamin D for fertility and pregnancy)
3 Benefits of Optimizing Vitamin D Levels
1. Weight Loss
- A few studies have shown a link between vitamin D levels and weight loss, possibly due to an appetite-suppressing effect.
- In one study, those who took a vitamin D supplement lost more weight than those taking a placebo.
2. Mood
- A growing body of research has linked Vitamin D and mood regulation, especially seasonal mood changes.
3. Inflammation
- Low levels of Vitamin D have been shown to increase inflammation and inflammatory markers in the body.
- Low levels have been linked to inflammatory diseases like Irritable Bowel, Multiple Sclerosis, Lupus and Alzheimer's.
This is my PSA to test Vitamin D levels and work closely with a practitioner to optimize them.
About the author
Dr. Courtney Ranieri, ND is a board-licensed naturopathic doctor and the founder of Somewhere Health. She earned her Doctor of Naturopathic Medicine at the Canadian College of Naturopathic Medicine in Toronto and holds an Honours Bachelor of Science from the University of Western Ontario. Her clinical focus spans hormonal health, fertility, digestion, and women's health, with advanced training in pelvic floor therapy and integrative fertility care.
