Rickets and vitamin D in children: why it is returning and what to do about it

What is rickets and why does it appear in sunny countries?

Rickets is a disease of growing bone. When vitamin D levels are too low, the gut absorbs far less calcium from food than the body needs, and the bones that are actively forming during childhood cannot mineralise properly. Instead of hard, straight bone, the growing skeleton produces soft, pliable tissue that bends under the child's own weight and takes on characteristic deformed shapes. The bones most visibly affected are the legs, the wrists, the ribs and the skull, because these are the sites of most active growth.

The paradox of rickets in countries like the UAE, Saudi Arabia, Kuwait and Jordan, where the sun is strong for most of the year, resolves when you look at how people actually live. Vitamin D is produced in the skin only when ultraviolet B radiation from the sun hits uncovered skin directly. Most children in the region spend the bulk of their waking hours indoors in air-conditioned buildings or cars. When they do go outside, clothing covers most of the skin, and sunscreen blocks the UV radiation that is left. A 2008 study of nutritional rickets in the UAE published in Pediatrics International found that active rickets was still being diagnosed in a country with year-round sun, and that the mechanism was inadequate actual skin exposure rather than inadequate sunshine.

A comprehensive 2018 review in Bone Reports of vitamin D status across the Middle East and North Africa documented widespread vitamin D deficiency among women of childbearing age and children across the region, making clear that geography and sun strength are far less important than behaviour and lifestyle when it comes to predicting who will and will not become deficient.

The mother's vitamin D: the connection that is often missed

A 2005 study published in the Journal of Pediatrics compared vitamin D levels in mothers of rachitic children against mothers of non-rachitic children in the UAE, and found that mothers whose children had developed rickets had significantly lower vitamin D levels themselves. This direct link means that a mother's deficiency is not her problem alone: it becomes her infant's problem through the same breastfeeding relationship that is otherwise so valuable.

A breastfed infant depends almost entirely on what the mother has stored during pregnancy and what passes into breast milk to meet their vitamin D needs. Breast milk contains very little vitamin D even when the mother is replete, and the amounts are insufficient to prevent deficiency in the infant without supplementation. A 2020 Cochrane systematic review on vitamin D supplementation for breastfed infants confirmed this clearly: breastfeeding alone is not protective against vitamin D deficiency, and daily supplementation of the infant is necessary from early in life.

This means the protective chain works best when both links are addressed: the mother's vitamin D status during pregnancy matters for the stores the newborn inherits, and the infant's supplement matters for the months that follow. A woman planning a pregnancy in this region, where deficiency is common, has good reason to have her vitamin D checked and discuss supplementation with her doctor well before delivery.

Signs of rickets: what to look for

Early rickets is largely silent. There is no obvious pain and no visible deformity in most cases at the outset. The first signs parents notice are often non-specific: delayed motor milestones such as being slow to sit, stand or walk compared to other children the same age, generalised muscle weakness, excessive sweating of the head during feeding in infants, and unusual irritability. These signs overlap with many other conditions but all of them warrant a visit to the paediatrician.

As rickets progresses, the bony changes become visible. Swelling of the wrists and ankles at the growth plates is an early skeletal sign. The legs may bow outward at the knees, producing the classic O-shaped (genu varum) or X-shaped (genu valgum) appearance, depending on where the softened bone bends. In the chest, swelling at the junction between the ribs and the cartilage produces a string of bead-like protrusions called the rachitic rosary. In young infants, the fontanelle (the soft spot on the top of the skull) may remain open longer than expected, and the skull itself may become softened (craniotabes).

Two signs that frequently bring children to the doctor and may indicate rickets are delayed tooth eruption and a flattening of the back of the skull from lying down. In girls, rickets affecting the pelvis can create narrowing that causes problems much later during childbirth. All of these consequences are avoidable with timely prevention. Carpenter and colleagues in their 2017 review of rickets in Nature Reviews Disease Primers describe the full clinical spectrum and emphasise that none of the typical presentations need to be seen if prevention is applied from infancy.

Which children are at highest risk of vitamin D deficiency?

Breastfed infants without a vitamin D supplement sit at the top of the risk hierarchy. A 2024 study of children at a tertiary hospital in Abu Dhabi published in Paediatrics and International Child Health found that exclusive breastfeeding without supplementation was one of the strongest factors associated with vitamin D deficiency in the study population. This is not a reason to discourage breastfeeding, which remains the ideal infant nutrition. It is a reason to routinely supplement every breastfed infant from the first weeks of life.

Children with darker skin need more sun exposure to produce the same amount of vitamin D as lighter-skinned children, because melanin (Melanin), the pigment that gives skin its colour, competes with vitamin D production for the same UV radiation. In a region where many children have naturally darker skin and also spend limited time with uncovered skin outdoors, these two factors combine to increase risk substantially. A paper by Wacker and Holick in Dermato-endocrinology (2013) examining the global relationship between sunlight and vitamin D status documented how skin pigmentation meaningfully affects synthesis rates and why supplementation is more important for darker-skinned populations living at any latitude.

Premature infants carry smaller reserves of vitamin D at birth because the fetus builds most of its stores from the mother during the last trimester. A baby born at 30 weeks has missed the final accumulation phase entirely. Preterm infants typically need supplements from as early as one month of age, at doses that the neonatal team will specify based on birth weight and gestational age.

How are vitamin D deficiency and rickets diagnosed?

The standard blood test is 25-hydroxy vitamin D (25-OH Vitamin D), which measures the body's stored form of the vitamin rather than the active form, which fluctuates too rapidly to be useful. Most guidelines define sufficiency as 50 nmol/L or above (equivalent to 20 ng/mL or above). Values between 30 and 50 nmol/L indicate insufficiency, and values below 30 nmol/L indicate frank deficiency. Some paediatric guidelines use 50 nmol/L as the lower limit of sufficiency and set a higher target of 75 nmol/L for at-risk groups.

When rickets is clinically suspected, the doctor will usually add measurement of calcium (Calcium) and phosphorus (Phosphorus) in blood and urine, and alkaline phosphatase (Alkaline Phosphatase), an enzyme that rises sharply in active rickets as bone formation struggles. X-rays of the wrist or knee show the characteristic changes at the growth plates, including widening, haziness and the cupping and fraying of the bone ends, which can appear before skeletal deformity is visible on external examination.

In smaller clinics across the region where vitamin D testing is not routinely available or is expensive, doctors sometimes make an empirical clinical diagnosis based on the age, feeding history, visible signs and elevated alkaline phosphatase, and start treatment without the full panel. This is a reasonable approach given the low cost of the supplement and the clear clinical picture in many cases. If you live in an area where testing is available, it is worth having a level checked before starting high-dose treatment, because it confirms the diagnosis and guides the dose.

Prevention doses by age

For prevention, not treatment: all breastfed infants need 400 international units (IU) of vitamin D per day, started within the first few weeks after birth and continued until diet is diverse enough to include adequate dietary sources. This recommendation is endorsed by multiple systematic reviews and paediatric societies worldwide, and is safe at this dose with no risk of toxicity. The Cochrane review of 2020 on vitamin D for breastfed infants confirmed its effectiveness for preventing deficiency and supporting bone health.

Infants on formula milk usually do not need an additional supplement if they are consuming 500 ml or more per day, because formula is fortified with around 40 to 50 IU per 100 ml. A child consuming less than that amount, or a child being partially breastfed, should receive a supplement to reach the 400 IU daily target. Your paediatrician can calculate this precisely based on the child's actual daily intake.

Children aged one to 18 years need around 600 IU daily when sun exposure is limited. In this region, where actual direct skin exposure to sunlight is low despite abundant sunshine, many paediatric specialists recommend year-round supplementation rather than the seasonal approach used in northern Europe, where winter sun is genuinely insufficient. A supplement taken daily through the year is simpler to maintain as a habit and prevents the dip in levels that occurs when families stop for the summer, reasoning incorrectly that the outdoor sun will cover the gap.

Treatment of established rickets: what to expect

Do not give your child high-dose vitamin D without a doctor's guidance. Vitamin D is fat-soluble and accumulates in the body. At doses far above the preventive range, it causes vitamin D toxicity (hypervitaminosis D), which raises blood calcium to dangerous levels, producing vomiting, abdominal pain, excessive thirst and in severe cases kidney damage. Treatment doses for confirmed rickets are many times higher than preventive doses and must be prescribed and monitored by a doctor.

Once the right treatment dose is given, calcium and phosphorus levels in the blood typically normalise within two to four weeks. Clinical signs such as wrist swelling and muscle weakness improve over the following months. X-ray evidence of healing at the growth plates appears by three to six months. Leg bowing in mild cases often improves substantially as the child grows and the bones remodel, but severe deformities that have been present for a long time may persist and occasionally require surgical correction.

Dietary sources of vitamin D are limited but worth including. Oily fish such as salmon, sardines and tuna provide meaningful amounts. Egg yolk and liver contain moderate quantities. In countries where food fortification programmes exist, vitamin D is added to milk, margarine and some juices. Check the labels of products available locally. Diet alone is unlikely to prevent deficiency in a breastfed infant or a child with very low sun exposure, but it adds a useful layer on top of a supplement.

Practical prevention in everyday regional life

Prevention starts before birth. A mother who is vitamin D deficient during pregnancy will deliver a baby with lower stores at birth, making supplementation even more important in the first months. Women planning a pregnancy have good reason to ask their doctor to check their vitamin D level and discuss supplementation. This is not an unusual request, and in this region given the documented prevalence of deficiency, it is a sensible precaution.

Sensible sun exposure is achievable within the constraints of regional life and cultural norms. The goal is not midday sun on fully uncovered skin. Thirty minutes in the early morning or an hour before sunset, with the forearms and face exposed without sunscreen during that specific window, allows the skin to produce meaningful amounts of vitamin D. The practical difficulty is that this level of regular outdoor time is simply not a feature of daily life for many urban families in the region, which is precisely why the supplement exists as the reliable fallback.

Vitamin D drops for infants are widely available at pharmacies across the region without a prescription, and the cost of a month's supply is low. The drops are given directly into the infant's mouth or on to the nipple before feeding. Starting them in the first weeks and continuing consistently through the first year and beyond is the most effective single action a parent can take to prevent rickets. Consistency matters: a daily drop given every day is far more effective than a larger dose given sporadically.

Sources

• Chakhtoura M, Rahme M, Chamoun N et al: Vitamin D in the Middle East and North Africa, Bone reports, 2018
• Abuhamad AY, Almasri N, Al Karaghouli Y et al: Vitamin D deficiency and associated demographic risk factors in children at a tertiary hospital in Abu Dhabi, Paediatrics and international child health, 2024
• Tan ML, Abrams SA, Osborn DA et al: Vitamin D supplementation for term breastfed infants to prevent vitamin D deficiency and improve bone health, The Cochrane database of systematic reviews, 2020
• Carpenter TO, Shaw NJ, Portale AA et al: Rickets, Nature reviews. Disease primers, 2017
• Rajah J, Jubeh JA, Haq A et al: Nutritional rickets and z scores for height in the United Arab Emirates: to D or not to D?, Pediatrics international, 2008
• Dawodu A, Agarwal M, Sankarankutty M et al: Higher prevalence of vitamin D deficiency in mothers of rachitic than nonrachitic children, The Journal of pediatrics, 2005
• Wacker M, Holick MF: Sunlight and Vitamin D: A global perspective for health, Dermato-endocrinology, 2013