5 Signs Of Vitamin D Deficiency In Children, Causes & Treatment

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Vitamin D deficiency in children can be detrimental to their proper growth and development. Vitamin D is vital for bone growth, neuronal health, and the proper functioning of muscles. It has also been found to participate in regulating immunity. Any deficiency of this fat-soluble vitamin may affect a child’s overall development and quality of life.

The per-day requirement of vitamin D is 600 IU (15mcg) for children aged between three and 18 years as directed in the dietary guidelines for Americans (2020-2025) (1) (2). Experts say that about one out of every ten US children is deficient in Vitamin D. The best method of getting the daily dose of vitamin D is sun exposure. Certain foods such as oily fish and fortified milk may also be included in children’s diet (3).

This post discusses the causes, symptoms, complications, and treatment strategies for Vitamin D deficiency in children.

Sign And Symptoms Of Vitamin D Deficiency In Children

The symptoms of vitamin D deficiency develop when the body’s vitamin D levels are quite low. The symptoms could vary depending on the severity of the deficiency. Below are some of the common signs and symptoms of vitamin D deficiency in children.

  1. Fatigue and tiredness: Low vitamin D levels in the body could trigger fatigue (4). Research has highlighted that vitamin D deficiency can weaken bones and muscles, making an individual prone to tiredness. These symptoms usually resolve upon vitamin supplementation (5).
  1. Generalized muscle pain: Vitamin D regulates muscle functions, and its deficiency is associated with muscle pain (myalgia) (6). However, how vitamin D deficiency causes muscle pain is still under research (7).
  1. Frequent infections: Research demonstrates that vitamin D deficiency can modulate innate and acquired immunity, raising the risk of autoimmunity (8). Enhanced autoimmunity puts an individual at risk of autoimmune diseases and recurrent infections, especially of the respiratory tract (9) (10).
  1. Impaired wound healing: Research shows that vitamin D has vital anti-inflammatory properties, which can hasten wound healing (11). A clinical study also demonstrated that vitamin D promotes the production of compounds necessary for the wound-healing process (12).
  1. Bone loss: Vitamin D facilitates calcium absorption, which mineralizes the bones and teeth. In severe vitamin D deficiency, the body’s calcium absorption decreases, and the parathyroid hormone levels increase, triggering calcium loss from bones. Due to the combined effect of reduced calcium absorption and increased bone loss, children develop nutritional rickets. Rickets is a condition where the bones soften, resulting in painful bone deformities that affect life quality (13).

In growing children, bone loss and muscle weakness could severely affect daily activities, such as walking, playing, and climbing stairs.

Possible Causes Of Vitamin D Deficiency In Children

The following factors and conditions could lead to vitamin D deficiency in children.

  1. Vitamin D deficient diet: Most foods don’t contain vitamin D, and it is why vitamin D fortification has become vital. However, several children, especially picky eaters, don’t get the required amounts of vitamin D even from fortified foods, increasing the risk of deficiency.
  1. Limited exposure to sunlight: Vitamin D, also known as the “sunshine vitamin,” is produced by converting the inactive vitamin D (cholecalciferol) to its active form (calcitriol) when the skin is exposed to UVB (ultraviolet B) rays. Children usually get 80 percent of their active vitamin D from sunlight (14). However, those who spend most of their time indoors or wear sunscreen while playing outside are at vitamin D deficiency risk.
  1. Cross-interaction with medicines: Corticosteroids and anti-seizure drugs are certain medications that may lower vitamin D levels in the body (15). If your child or teen is on any medication, consult your healthcare provider or doctor. They are most likely to suggest a supplement, especially if the child’s vitamin D levels are already insufficient or low.
  1. Physiological problems: Certain conditions, such as abnormal liver and kidney functions, cystic fibrosis, inflammatory bowel diseases, and celiac disease, could lead to poor absorption of dietary vitamin D by the body. It may gradually lead to vitamin D deficiency.

Diagnosis Of Vitamin D Deficiency In Children

A doctor will order a blood test to measure 25-hydroxy vitamin D levels in the body. Below is the representation of the vitamin D status based on its serum levels in nanograms per milliliter (ng/mL) (1).

Vitamin D statusLevels (ng/mL)
Severely deficientLess than 12
InsufficientBetween 12 to 20
SufficientGreater than or equal to 20

Source: National Institute Of Health 

Treatment Of Vitamin D Deficiency In Children

Treatment for vitamin D deficiency involves addressing the cause of deficiency and providing supplementation. The supplementation will include intake of vitamin D tablets or mixtures that the child has to either take daily (low dose) or weekly or monthly once (high dose). The dosage depends on the cause of the deficiency and the overall health of the child.

If your child is already consuming a multivitamin or is on any medication, inform your doctor so that they can adjust the dosage accordingly. Additionally, they will advise you to add vitamin D and calcium-rich foods to the daily diet with 15 to 20 minutes of sunlight exposure a few days a week or daily.

Possible Complications Of Vitamin D Deficiency

Untreated vitamin D deficiency may increase the risk of the following conditions.

  • Hypocalcemia (low calcium levels)
  • Hypophosphatemia (low phosphate levels)
  • Rickets (softening of the bones)
  • Poor physical growth and development
  • Severe bone deformities limiting a child’s movement

How To Prevent Vitamin D Deficiency In Children?

Optimum sun exposure and eating a well-balanced diet containing vitamin D-fortified and calcium-rich foods, such as fortified milk, breakfast cereal, and cheese, are sufficient to prevent vitamin D deficiency.

Below are some natural food sources of vitamin D that contain vitamin D without any fortification (16) (17).

FoodVitamin D content (IU) in 3.5oz. (100g)
Fresh salmon (wild)600 – 1000
Fresh salmon (farmed)100 – 250
Sardines (canned)300
Tuna (canned)236
Mackerel (canned)250
Shitake mushroom (fresh)100
Shitake mushroom (canned)1600
Egg (hard-boiled)20

Note: 1IU vitamin D = 0.025mcg (micrograms)

Source: American Academy of Pediatrics (AAP)

If you are unsure about your child’s vitamin D intake, consult a pediatric nutritionist who may provide a diet plan to treat and mitigate vitamin D deficiency in your child.

Frequently Asked Questions

1. Which fruit is rich in vitamin D?

Although vitamin D is not found abundantly in many fruits, oranges (in the form of fortified orange juice) are good sources of vitamin D (18).

2. Do egg yolks have vitamin D?

Yes, egg yolks are considered rich sources of vitamin D (19).

3. How long does it take to correct a vitamin D deficiency?

For children with mild to moderate vitamin D deficiency, the doctor may guide them with treatment dosages per the child’s age and severity for a few weeks. However, if the deficiency is severe (such as leading to rickets), the dosages may increase and continue for around three months (20).

Vitamin D is critical for several vital functions in the body, such as bone growth, muscle functioning, and immunity. Vitamin D deficiency in children may lead to fatigue, muscle pain, and frequent infections. Hence, it is essential to check your children’s Vitamin D levels regularly to catch any deficiency early and treat it before it leads to further problems. Vitamin D deficiency generally occurs due to limited sun exposure, an unbalanced diet, and physiological problems. However, timely supplementation and sunlight exposure may help improve Vitamin D levels in children.

Key Pointers

  • Symptoms of vitamin D deficiency in children are fatigue, muscle pain, and recurring infections.
  • It can be diagnosed with a blood test and treated by sunlight exposure, a well-balanced diet, and supplements.
  • If not taken care of in time, the deficiency can lead to poor growth and bone deformities.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1. Vitamin D; NIH
2. Dietary Guidelines for Americans, 2020-2025; USDA
3. Memo to Pediatricians: Screen All Kids for Vitamin D Deficiency, Test Those at High Risk; Johns Hopkins Medicine
4. Could a vitamin or mineral deficiency be behind your fatigue?; Harvard Health Publishing
5. Satyajeet Roy et al.; Correction of Low Vitamin D Improves Fatigue: Effect of Correction of Low Vitamin D in Fatigue Study (EViDiF Study); NCBI
6. Jenny E. Guntona and Christian M. Girgisa; Vitamin D and muscle; NCBI
7. Sarah E. Tague et al.; Vitamin D Deficiency Promotes Skeletal Muscle Hypersensitivity and Sensory Hyperinnervation; NCBI
8. Cynthia Aranow; Vitamin D and the Immune System; NCBI
9. Cameron F. Gunville et al.; The Role of Vitamin D in Prevention and Treatment of Infection; NCBI
10. ApsiaRuhi and Dr. Tudumu Ananth; A study of Vitamin-D and nutritional status in recurrent respiratory tract infections in children 1-5 years of age; Pediatric Review: International Journal of Pediatric Research
11. YiFeng Yuan et al.; Vitamin D ameliorates impaired wound healing in streptozotocin-induced diabetic mice by suppressing NF-κB-mediated inflammatory genes; NCBI
12. Jie Ding et al.; Synergistic effect of vitamin D and low concentration of transforming growth factor-beta 1, a potential role in dermal wound healing; NCBI
13. Symptoms, Rickets and osteomalacia; NHS
14. Vitamin D: what you need to know; Raising Children
15. Uwe Gröber and Klaus Kisters; Influence of drugs on vitamin D and calcium metabolism; NCBI
16. Vitamin D: On the Double; American Academy of Pediatrics
17. Dietary Supplement Ingredient Database; NIH
18. Food Sources of Vitamin D; Dietary Guidelines for Americans.
19. Vitamin D; National Library of Medicine.
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Dr. Richa A Kaushal

Dr. Richa Kaushal works as an Assistant Professor in the Department of Pediatrics at UCSF Fresno, California. She is also a physician at Community Regional Medical Center, Fresno, California, and Clovis Community Hospital, Clovis, California. She did her Pediatric Residency training at William Beaumont Hospital at Oakland University William Beaumont School of Medicine in Michigan. Dr. Kaushal’s main areas of... more

Swati Patwal

Swati Patwal is a clinical nutritionist and toddler mom with over eight years of experience in diverse fields of nutrition. She started her career as a CSR project coordinator for a healthy eating and active lifestyle project catering to school children. Then she worked as a nutrition faculty and clinical nutrition coach in different organizations. Her interest in scientific writing... more