What is vitamin D deficiency?
Vitamin D deficiency is a condition where the body does not have enough vitamin D, a nutrient that is essential for maintaining strong bones, immune function, and overall health. Vitamin D is obtained through exposure to sunlight, diet, and supplements. A deficiency in vitamin D can lead to a range of health problems, including osteoporosis, diabetes, and multiple sclerosis.
What does the research say?
Research has shown that vitamin D deficiency is a significant public health concern, with an estimated 40% of adults in the United States having a deficiency [5]. Studies have also found that vitamin D deficiency is associated with an increased risk of multiple sclerosis [1], with low vitamin D levels being a risk factor for disease activity [2]. Additionally, research has shown that high-dose vitamin D supplementation can reduce disease activity in patients with clinically isolated syndrome, a condition that can lead to multiple sclerosis [2]. Other studies have found that vitamin D deficiency is associated with an increased risk of diabetes [6], and that supplementation with vitamin D can improve insulin sensitivity and beta-cell function in people with prediabetes [6]. However, it is also important to note that high levels of vitamin D can increase the risk of kidney stones [7].
Practical tips you can try
To prevent or treat vitamin D deficiency, there are several practical steps you can take. Firstly, spend time outdoors, as exposure to sunlight can help your body produce vitamin D. Secondly, include vitamin D-rich foods in your diet, such as fatty fish, egg yolks, and fortified dairy products. Thirdly, consider taking a vitamin D supplement, especially during the winter months or if you have a limited diet. However, it is essential to consult with your doctor before starting any supplements, as high doses can be toxic. Additionally, if you have a history of kidney stones, you should be cautious when taking vitamin D supplements, as they may increase the risk of stone formation [7].
When to see a doctor
If you are experiencing any symptoms of vitamin D deficiency, such as bone pain, muscle weakness, or fatigue, you should see a doctor. Additionally, if you have a family history of vitamin D deficiency or have a medical condition that increases your risk of deficiency, you should consult with your doctor about getting tested. Children and adolescents with vitamin D deficiency may not have specific symptoms, but they may be at risk of developing rickets or other health problems [8]. If you are concerned about your vitamin D levels or have questions about supplementation, it is always best to consult with a healthcare professional.
References
[1] Thompson Alan J, Baranzini Sergio E, Geurts Jeroen, Hemmer Bernhard, Ciccarelli Olga. Multiple sclerosis. Lancet (London, England). 2018. PMID: 29576504 [2] Thouvenot Eric, Laplaud David, Lebrun-Frenay Christine, Derache Nathalie, Le Page Emmanuelle. High-Dose Vitamin D in Clinically Isolated Syndrome Typical of Multiple Sclerosis: The D-Lay MS Randomized Clinical Trial. JAMA. 2025. PMID: 40063041 [3] Passeron T, Bouillon R, Callender V, Cestari T, Diepgen T L. Sunscreen photoprotection and vitamin D status. The British journal of dermatology. 2019. PMID: 31069788 [4] Olek Michael J. Multiple Sclerosis. Annals of internal medicine. 2021. PMID: 34097429 [5] Marino Rose, Misra Madhusmita. Extra-Skeletal Effects of Vitamin D. Nutrients. 2019. PMID: 31252594 [6] Rasouli Neda, Brodsky Irwin G, Chatterjee Ranee, Kim Sun H, Pratley Richard E. Effects of Vitamin D Supplementation on Insulin Sensitivity and Secretion in Prediabetes. The Journal of clinical endocrinology and metabolism. 2022. PMID: 34473295 [7] Letavernier Emmanuel, Daudon Michel. Vitamin D, Hypercalciuria and Kidney Stones. Nutrients. 2018. PMID: 29562593 [8] Fischer Philip R, Johnson Casey R, Leopold Kaitlin N, Thacher Thomas D. Treatment of vitamin D deficiency in children. Expert review of endocrinology & metabolism. 2023. PMID: 37861060
⚠️ Medical Disclaimer
The information provided in this article is for general purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare professional with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read in this article.