5 signs you need more vitamin D 

woman with sun shining on her

Vitamin D deficiency is one of the most common nutrient deficiencies in the US, but the signs of low intake aren’t always obvious. If you’re noticing changes in your body or increased discomfort, chat with your doctor. It may be a sign that you’re lacking some important nutrients, like vitamin D. 

Here’s 5 signs that you may need to up your vitamin D intake. 

What is vitamin D? 

Vitamin D is an essential fat-soluble vitamin, meaning it’s absorbed in your bloodstream and can be stored in your tissues. It plays a role in many different processes in your body, including maintaining healthy bones, immunity, mood and even sexual wellness. It’s nicknamed the sunshine vitamin, because your body can produce it on its own when your skin is exposed to the sun’s UVB rays. And while your body is able to make vitamin D – exposure to the sun isn’t always a useful source.  

Who gets vitamin D deficiency?  

Living in the northern latitude, having a darker skin tone, wearing UV-blocking SPF and age can all make it hard to get vitamin D from the sun.  Given all these risk factors, it makes sense that  42% of U.S. adults are deficient in this key vitamin. If you’re worried you might be low, here’s some symptoms to look out for: 

5 signs your vitamin D might be low 

1. Bone weakness 

This probably isn’t surprising, as vitamin D’s role in bone health is well-known. Not only does the sunshine vitamin play a major role in bone development (vital for calcium absorption), but also in preserving bone health. Symptoms of achy bones, especially in your lower back might be a sign that you’re not getting enough vitamin D in your diet.2 Of course this doesn’t apply if you’ve slipped while walking or lifted heavy objects, but if you’re having trouble pinpointing why it’s happening – it’s best to make an appointment with your doctor and get your levels checked.   

2. Sore muscles 

The root cause of sore muscles or weakness can be linked to many different reasons: stretching incorrectly, intense exercise or even not working out enough. But if none of these reasons add up, those aching muscles could also be a sign your low in Vitamin D.  Scientists believe vitamin D plays a part in your body’s pain signaling pathway, though more research is needed. Your body has nerve cells called nociceptors that recognize pain – and scientists think vitamin D plays a role in how these cells communicate with each other. What does that mean?  Low vitamin D levels can trigger symptoms of muscle soreness and weakness.  

3. Fatigue and poor sleep 

Experiencing fatigue and poor sleep every now and then is just a natural part of life. But if you’re facing unexplained tiredness, it might be related to inadequate levels of vitamin D, according to a study.  

Not just that, but it can be affecting your sleep too. And while quality shuteye can be disrupted because of stress or from scrolling a little too long on TikTok (hey, no judgement!), but if sleep has been a nightly struggle for some time now, it could be related to low vitamin D (especially during the winter months). A small study linked low levels of vitamin D to poorer sleep quality, waking up more frequently and delayed bedtimes.  

4. Impaired Immune Function 

When we start feeling the sniffles coming on, we often reach for supplements such as vitamin C or zinc. And while these do play an important role in your immune response – we can’t overlook vitamin D. Your immune cells need vitamin D to function properly. Researchers are still figuring exactly how vitamin D helps those immune cells but if you’re someone who’s levels aren’t quite up to par – you may have a harder time fighting and recovering from colds or infections.5  

5. Decreased Libido 

A decrease in sex drive can happen for many reasons, usually reasons that we’re aware of or can be easily identified. Anything from excessive stress, fatigue or changes in health can all have an impact. But if you’re noticing a decrease in libido, a vitamin D deficiency could also be the culprit. Low Vitamin D levels may influence sex hormones, causing less sexual desire according to a small study.  

Sources of vitamin D 

  • Salmon 
  • Cod liver oil 
  • Tuna  
  • Milk 
  • Eggs 
  • Fortified orange juice 
  • Fortified cereal 


Vitamin D is undoubtedly crucial for many functions in your body, but as important as it is, it’s also a nutrient many of us struggle to get enough of. And while the signs and symptoms of low D aren’t always obvious, if you’re noticing any unexplainable changes, it’s best to check with your doctor to ensure your levels are within a health range. If they’re not- adding a supplement to your routine might help.   

Learn more about vitamins, read 4 important B vitamins for brain health

About Natalie

Natalie is a nutritionist with a Bachelor’s in Nutrition and Dietetics from the University of North Florida. Natalie believes that proper nutrition doesn’t have to be complicated and is determined to help others reach their health goals. 

Do you have questions about supplements? Reach out to one of our experts, or take Persona’s free nutrition assessment, and learn exactly what you need to take your wellness to the next level.    

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.     

This information is not intended as a substitute for the advice provided by your physician or other healthcare professional, or any information contained on or in any product label or packaging. Do not use the information from this article for diagnosing or treating a health problem or disease, or prescribing medication or other treatment. Always speak with your physician or other healthcare professional before taking any medication or nutritional, herbal, or homeopathic supplement, or using any treatment for a health problem. If you have or suspect that you have a medical problem, contact your health care provider promptly. Do not disregard professional medical advice or delay in seeking professional advice because of something you have read in this article.       


  1. Office of Dietary Supplements – Fact Sheet for Health Professionals: Vitamin D. (n.d.). Retrieved January 9, 2023, from Vitamin D – Health Professional Fact Sheet (nih.gov) 
  2. Sizar O, Khare S, Goyal A, et al. Vitamin D Deficiency. [Updated 2022 Jul 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532266/ 
  3. Rejnmark L. Effects of vitamin d on muscle function and performance: a review of evidence from randomized controlled trials. Ther Adv Chronic Dis. 2011 Jan;2(1):25-37. doi: 10.1177/2040622310381934. PMID: 23251739; PMCID: PMC3513873. 
  4. Nowak A, Boesch L, Andres E, Battegay E, Hornemann T, Schmid C, Bischoff-Ferrari HA, Suter PM, Krayenbuehl PA. Effect of vitamin D3 on self-perceived fatigue: A double-blind randomized placebo-controlled trial. Medicine (Baltimore). 2016 Dec;95(52):e5353. doi: 10.1097/MD.0000000000005353. Erratum in: Medicine (Baltimore). 2017 Jan 20;96(3):e6038. PMID: 28033244; PMCID: PMC5207540. 
  5. Aranow C. Vitamin D and the immune system. J Investig Med. 2011 Aug;59(6):881-6. doi: 10.2310/JIM.0b013e31821b8755. PMID: 21527855; PMCID: PMC3166406. 
  6. Zhao D, Ouyang P, de Boer IH, Lutsey PL, Farag YM, Guallar E, Siscovick DS, Post WS, Kalyani RR, Billups KL, Michos ED. Serum vitamin D and sex hormones levels in men and women: The Multi-Ethnic Study of Atherosclerosis (MESA). Maturitas. 2017 Feb;96:95-102. doi: 10.1016/j.maturitas.2016.11.017. Epub 2016 Nov 29. PMID: 28041602; PMCID: PMC5218632. 

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