Vitamin D is a nutrient which plays an essential role in every stage of the life cycle and has the potential to influence a wide range of health outcomes given that nearly every cell in the body has a vitamin D receptor. Our bodies need Vitamin D to be able to absorb calcium from our diet to build strong bones which are the building blocks of a healthy body, and to make muscles move. The extra-skeletal benefits of Vitamin D have received much attention recently. Adequate levels of vitamin D help to reduce the risk of autoimmune diseases, infections- such as upper and lower respiratory tract infections, gastrointestinal infections, asthma, cardiovascular diseases, multiple sclerosis, type 2 diabetes, mental health issues and some types of cancers of the breast, colon, prostrate and ovaries.

Vitamin D comes in 2 different forms- D2 (Ergocalciferol) and D3 (cholecalciferol). The main sources are by skin synthesis and dietary sources. Skin synthesis varies by factors such as season, time of day, latitude, altitude, sun-screen use and skin pigmentation. Dietary sources of vitamin D include oily fish (such as salmon), eggs, sundried mushrooms, and certain food fortified with vitamin D such as milk, fruit juices, cereals and margarine.

Vitamin D deficiency is a worldwide problem across all age groups affecting newborns up to the elderly. Recent studies from all around the world have shown deficiency of vitamin D in newborns and their mothers. Vitamin D deficiency during pregnancy has been reported to be associated with a number of poor pregnancy outcomes which include intrauterine growth retardation, premature labor, pregnancy induced hypertension, low birth weight and caesarean section. Mounting epidemiological evidence shows that vitamin D deficiency during infancy is associated with autoimmune diseases later in life.

Not enough vitamin D and calcium in growing children can make bone growth centers weak , preventing the bones from growing straight, or can make the bones too weak to support a child’s body weight resulting in broken bones. Older children with vitamin D deficiency are generally asymptomatic, but can have hormonal abnormalities of the parathyroid gland and changes in the growth plates of bones. Adolescents deserve a special mention as it is a crucial time for bone development and growth. Particular attention to vitamin D deficiency is important because it has been linked to increased blood pressure, increased blood sugar levels and obesity leading to metabolic syndrome.

Risk factors for deficiency include pregnant women especially multiple and twin pregnancies, prolonged breast feeding without vitamin D supplementation in the baby, breastfeeding mothers with low vitamin D levels, adolescents, obesity and low sunlight exposure. Reduced sunlight exposure can occur in northern latitudes, season- winter, Asian and African descent due to increased pigmentation, wearing concealing clothing, excessive use of sunblock and inpatient care of chronically ill patients. Limited diet (vegetarians and vegans), exclusion diets (due to milk allergy), malabsorption, chronic kidney and liver diseases and some medications (ant epilepsy and TB medications) can also predispose to vitamin D deficiency. Although the main source is sunlight, diet is a source of calcium.

Treatment of vitamin D deficiency and its complications require a team approach including pediatric and orthopedic specialists. The general recommendations suggest vitamin D supplementation for all children from six months to 5 years of age. Exclusively breast fed infants need supplementation soon after birth. Vitamin D has been difficult to obtain in treatment doses but now higher dose tablets and capsules of 400, 1000, 10000 and 50,000 IU are readily available. It is essential to check that the child has adequate calcium intake in the diet and maintenance vitamin D is required long term after treatment of vitamin D deficiency; at least until they stop growing.

Other measures include vitamin D fortification of highly consumed food, milk and milk products. Educational endeavors about sensible sun exposure to improve vitamin D status should also be implemented among the general population.