Vitamin D is produced endogenously when the human skin is exposed to the sun’s rays. The sun rays are a significant source of Vitamin D. Vitamin D is an essential, fat-soluble vitamin for the human health and growth of bones. It plays a critical role in regulating calcium concentrations in the body, absorbs calcium and phosphate from food, reduces inflammation, and helps regulate cell growth. Vitamin D triggers our body’s immune cells to produce antibodies, strengthening the immune system. Vitamin D helps in diabetes management by regulating insulin levels. Vitamin D assists in maintaining joint and muscle comfort and maintaining a healthy mood and supports breast, colon, and prostate health. Vitamin D increases muscle protein synthesis, possibly by activating second messengers and phosphorylation. The two significant forms of Vitamin D that are important for humans are vitamin D2 [ergocalciferol] and vitamin D3.
The concentration of serum 25-hydroxyvitamin D determines the level of Vitamin D in our body. The exact concentration of 25-hydroxyvitamin D required for optimum health is still under study. However, studies have shown that when the level of serum circulating 25-hydroxyvitamin D (25-(OH)D) is less than 20 ng/mL, the person is at high risk of getting Vitamin D deficiency. According to the US endocrine society, if the level of Vitamin D is 21-29 ng/mL, then the condition is called Vitamin D insufficiency. On the other hand, vitamin D becomes toxic if its levels are more than 150 ng/mL.
Scientific studies have found that many children and teens suffer from vitamin D deficiency and insufficiency. For example, a paper published in the Annals of Pediatric Endocrinology & Metabolism, 2016, found that children aged six to twelve years have high chances of having Vitamin D deficiency. The study also concluded that Spring and Winter seasons are risk factors for Vitamin D deficiency. This article stays on the same track and gives an overview of the risk factors, health complications, symptoms, recommended dietary intake, and treatment for Vitamin D deficiency in children.

Vitamin D deficiency risk factors in children
The following factors can be the risk factors for Vitamin D deficiency in children:

  • Children are not getting exposed to sun rays during the winter and spring season, keeping their skin covered, or staying inside the house all day long without any physical activity.
  • Children do not have Vitamin D-rich foods in their diet.
  • Children breastfed by mother having Vitamin D deficiency. Breast milk contains a minimal amount of Vitamin D.
  • Infants who ingest less than 1000 mL of infant formula a day
  • Children who are obese and do not indulge in physical activities during the morning
  • Children have medical conditions like coeliac disease, cystic fibrosis, diabetes, liver disease, and kidney disease.
  • Children are having dark skin.
  • Children who regularly use sunscreen having an SPF of 15 or more.
  • Children who take medications that can affect Vitamin D levels in the body.
  • Children hospitalized for a longer duration due to critical illness or children attending a school that limits outside play.

Health Complications in Children due to Vitamin D deficiency
Vitamin D deficiency in children affects the mineralization of the bone matrix (osteoid) in growing bone, a condition called Rickets. Loss in minerals of the bone matrix leads to hypocalcemia or hypophosphatemia, which affects the development of epiphyseal growth plate. Although seen in infancy, Rickets can also occur during the pubertal growth spurt and adolescence. Undiagnosed and untreated Vitamin D deficiency can affect the functioning of multiple organs. Rickets, if untreated, can cause skeletal deformities like permanent dwarfing, bowing deformity of long bones, lower rib indentation, diffused bone pain, and back deformities. Apart from Rickets, other health complications that can result if Vitamin D deficiency is left untreated in children includes

  • Brittle bones
  • Premature osteoporosis in later life
  • Loss in bone density
  • Suppressed Immunity that increases chances of infection
  • Distorted pelvis causing obstetric complications for females in later life
  • Increased risk of Type I Diabetes in later life
  • Increased risk of multiple sclerosis and seizures
  • If there is a genetic tendency of autism in a family, then Vitamin D deficiency may allow autism to express itself.

Symptoms of Vitamin D deficiency
The symptoms of Vitamin D deficiency in children include:

  • Lethargy
  • Irritability
  • Growth failure
  • Myalgia (pain in the muscles) along with muscle cramps
  • Skeletal deformities like permanent dwarfing, bowing deformity of long bones, lower rib indentation, diffused bone pain, and back deformities.
  • Depression
  • Fatigue
  • Alopecia
  • Decreased Immunity

What is the recommended Vitamin D intake for Children?

GroupAge (in years)Recommended Intake
Pregnant and Lactating Women Minimum 600 IU/Day
InfantsLess than one yearAt least 400 IU/day
ChildrenAbove one year of age and below 19 years600 IU/ day
Adults19-50Minimum 600 IU/Day
Elderly50-70Minimum 600 IU/Day
ElderlyAbove 70 years800 IU/day

Source: Endocrine Society and Metabolic Health Digest

Treating Vitamin D deficiency in Children
The following methods can cure vitamin D deficiency in children:

  • Minimum 30-minute exposure of the face, arms, and back of the children to sunlight daily without any clothes or covering material. This will give 90% of the daily requirement of Vitamin D.
  • Morning walks and physical exercise must be a part of daily activities in children.
  • Choosing the right sunscreen for your child’s skin is essential. Talk to your physician and follow their advice.
  • Children should have a diet rich in Vitamin D. Since Vitamin D is present only in a few food items; thus, children, under the advice of nutritionists and physicians, can have the following foods in their balanced diet:
    • Fortified milk products (milk, cereal, and yogurt)
    • Shrimp
    • Fortified orange juice
    • Fortified cereals & oatmeal
    • Wild mushrooms
    • Cod-liver oil
    • Fatty fish (rohu, trout, tuna, salmon, and herring)
    • Egg Yolks
    • Goat Liver
  • Too much Vitamin D can cause a problem in the child; thus, if a physician has prescribed any Vitamin D supplements(tablets), take them as per the advice given by the physician.


  1. Roh, Y. E., Kim, B. R., Choi, W. B., Kim, Y. M., Cho, M. J., Kim, H. Y., Park, K. H., Kim, K. H., Chun, P., Kim, S. Y., & Kwak, M. J. (2016). Vitamin D deficiency in children aged 6 to 12 years: single center’s experience in Busan. Annals of pediatric endocrinology & metabolism, 21(3), 149–154.
  2. Vitamin D Deficiency in Children, Maura Keller, December 2012. Accessed at
  3. Balasubramanian, S., Dhanalakshmi, K., & Amperayani, S. (2013). Vitamin D deficiency in childhood—A review of current guidelines on diagnosis and management. Indian pediatrics, 50(7), 669-675.
  4. Vitamin D insufficiency and deficiency in children and adolescents. Accessed at
  5. Vitamin D in Toddlers, Preschool Children, and Adolescents. Accessed at
  6. Vitamin D: what you need to know. Accessed at
  7. Weydert J. A. (2014). Vitamin D in Children’s Health. Children (Basel, Switzerland), 1(2), 208–226.
  8. Endocrine Society publishes clinical practice guidelines for vitamin D deficiency. Accessed at,mL%20to%2029%20ng%2FmL.
  9. Memo to Pediatricians: Screen All Kids for Vitamin D Deficiency, Test Those at High Risk. Accessed at
  10. Cashman K. D. (2007). Vitamin D in childhood and adolescence. Postgraduate medical journal, 83(978), 230–235.