IMPACT OF VITAMIN D FORTIFIED MILK VERSUS REGULAR MILK ON INSULIN RESISTANCE IN ADOLESCENTS

Zubair  Ahmad; Murtaza Khodadadi; Ayesha Asghar

Authors

Zubair Ahmad Services Hospital Jail Road Lahore, Pakistan. Author https://orcid.org/0009-0009-2295-2495
Murtaza Khodadadi Comsats University Islamabad, Pakistan. Author
Ayesha Asghar Bahria University College of Medicine, Pakistan. Author

Keywords:

Adolescent Health, Dietary Supplements, Insulin Resistance, Milk, Nutritional Fortification, Randomized Controlled Trial, Vitamin D

Abstract

Background: Insulin resistance during adolescence is a growing concern due to increasing rates of obesity and sedentary lifestyles. Vitamin D deficiency has been linked to impaired glucose metabolism and insulin resistance, suggesting a potential role for nutritional fortification strategies. Milk, as a staple food in adolescent diets, provides a practical vehicle for vitamin D fortification.

Objective: To determine whether daily intake of vitamin D–fortified milk improves insulin sensitivity among adolescents with early metabolic risk compared to regular milk consumption.

Methods: A six-month study in South Punjab followed 132 teenagers, aged 12 to 18, to explore the effects of vitamin D. The adolescents were randomly divided into two groups: one group drank a daily serving of milk fortified with vitamin D, while the other consumed regular milk. Researchers measured their fasting blood sugar, insulin, and vitamin D levels at the start and end of the trial, also calculating insulin resistance. The results were then compared using standard statistical tests to identify any meaningful differences between the groups.

Results: The fortified milk group showed a significant increase in serum 25(OH)D levels (18.6 ± 4.2 to 32.4 ± 5.1 ng/mL, p < 0.001) compared to minimal change in the regular milk group (p = 0.08). HOMA-IR decreased notably in the fortified group (2.91 ± 0.35 to 2.21 ± 0.29, p < 0.001), while only slight reduction occurred in controls (p = 0.09). Fasting glucose decreased significantly in the fortified group (p = 0.002). A strong inverse correlation was found between changes in 25(OH)D and HOMA-IR (r = –0.61, p < 0.001).

Conclusion: Vitamin D–fortified milk effectively improved vitamin D status and insulin sensitivity in adolescents with early metabolic risk. Fortification represents a feasible, low-cost nutritional intervention to mitigate insulin resistance in youth.

Author Biographies

Zubair Ahmad, Services Hospital Jail Road Lahore, Pakistan.

Senior Registrar Pediatrics Department, Services Hospital Jail Road Lahore, Pakistan.
Murtaza Khodadadi, Comsats University Islamabad, Pakistan.

4th semester, MSC, Microbiology and Immunology, Comsats University Islamabad, Pakistan.
Ayesha Asghar, Bahria University College of Medicine, Pakistan.

1st year mbbs student at Bahria University College of Medicine, Pakistan.

References

1. Singh A, Singh NJEJoP. Vitamin D intervention as a curative measure for glucose intolerance in obese children and adolescents: a systematic review on randomized control trials. 2024;183(4):1475-83.

2. Zhu L, Li S, Zhong L, Xu S, Zhu HJEJoN. Optimal vitamin D supplement dosage for improving insulin resistance in children and adolescents with overweight/obesity: a systematic review and network meta-analysis. 2024;63(3):763-75.

3. Rashidmayvan M, Sahebi R, Avan A, Sharifan P, Esmaily H, Afshari A, et al. Double blind control trial of vitamin D fortified milk on the expression of lncRNAs and adiponectin for patients with metabolic syndrome. 2023;15(1):9.

4. Street ME, Casadei F, Di Bari ER, Ferraboschi F, Montani AG, Shulhai A-M, et al. The Role of Nutraceuticals and Probiotics in Addition to Lifestyle Intervention in the Management of Childhood Obesity—Part 1: Metabolic Changes. 2025;17(10):1630.

5. Al-Hetar MA, Rusli N, Kamaruzzaman MA, Al-Goshae H, Wan Ngah WZ, Shah SA, et al. Evaluating the Role of Vitamin D in Prediabetes Management, Insights from RCTs in the MENA Region: A Comprehensive Systematic Review. 2025;14(4):1239.

6. ELBanna MM, Kamel DM, Shaaban A, Botla AM, Hamoda REJIJoK, Science S. Effect of Yoga Training and High Probiotic Food Supplements on Insulin-Resistance in Polycystic-Ovarian-Syndrome: A Randomized Controlled Trial. 2024;12(3):52.

7. Maguolo A, Gabbianelli R, Maffeis CJEJoCN. Micronutrients in early life and offspring metabolic health programming: a promising target for preventing non-communicable diseases. 2023;77(12):1105-12.

8. Jubran N, Alanazi HQS, Al Anazi ADS, Alruwaili WMD, Al-Anzi TA-HJ, Al-Anzi AAKJJoIC, et al. Impact of vitamin D supplementation on the glycemic control of pre-diabetic individuals. 2024;7(S6):440.

9. Kosmas CE, Bousvarou MD, Kostara CE, Papakonstantinou EJ, Salamou E, Guzman EJJoIMR. Insulin resistance and cardiovascular disease. 2023;51(3):03000605231164548.

10. Leziak A, Lipina J, Reclik M, Kocelak PJM. Dietary Modulation of Metabolic Health: From Bioactive Compounds to Personalized Nutrition. 2025;15(9):624.

11. Yang LJFie. Decreased serum levels of 25-OH vitamin D and vitamin K in patients with type 2 diabetes mellitus. 2024;15:1412228.

12. Roosyidah DA, Habibah Ka, Syauqy A, Sulchan M, Nugroho KH, Pramono AJN, et al. Dietary patterns and their role in regulating insulin sensitivity in individuals with overweight or obesity: a narrative review. 2025:1-21.

13. Cimini FA, Sentinelli F, Oldani A, Barchetta I, Cavallo MGJIJoMS. Adipose Tissue Dysfunction and Metabolic Diseases: The Role of Vitamin D/Vitamin D Receptor Axis. 2025;26(21):10256.

14. Li A, Han X, Liu L, Zhang G, Du P, Zhang C, et al. Dairy products and constituents: a review of their effects on obesity and related metabolic diseases. 2024;64(33):12820-40.

15. Ahmed A, Saleem MA, Saeed F, Afzaal M, Imran A, Akram S, et al. A comprehensive review on the impact of calcium and vitamin D insufficiency and allied metabolic disorders in females. 2023;11(9):5004-27.

16. Monapati S, Kaki P, Gurajapu MS, Subhas PG, Kudipudi HBJD, Candidates D. The effects of vitamin D on preventing hyperglycemia and a novel approach to its treatment. 2023;2(4):923-36.

17. Feng Y, Zhou W, Niu YJI. Effects of vitamin D supplementation combined with exercise on glucolipid metabolism in adults: A meta-analysis. 2025;28(9).

18. Dumbre D, Upendra S, Zacharias BSJPHN. Unraveling the Relationship Between Vitamin D and Noncommunicable Diseases: A Systemic Review and Meta‐Analysis. 2025;42(3):1302-14.

19. Yin W-j, Wang P, Ma S-s, Tao R-x, Hu H-l, Jiang X-m, et al. Vitamin D supplementation for cardiometabolic risk markers in pregnant women based on the gestational diabetes mellitus or obesity status: a randomized clinical trial. 2024;63(7):2599-609.

20. Wu Y, Zeng Y, Zhang Q, Xiao XJN. The role of maternal vitamin D deficiency in offspring obesity: a narrative review. 2023;15(3):533.

21. Reytor-González C, Simancas-Racines D, Campuzano-Donoso M, Castano Jimenez J, Román-Galeano NM, Sarno G, et al. Harnessing nutrition to combat MASLD: a comprehensive guide to food-based therapeutic strategies. 2025;36(1):2496499.