Why it occurs: not only the sun
Vitamin D enters the body in two ways: it is formed in the skin under the influence of ultraviolet radiation and comes from food and supplements. In a child of the first year of life, both pathways work poorly, and this is determined by physiology itself, and not by the mistakes of the parents.
- Breast milk contains very little vitamin D, a known characteristic that has nothing to do with the mother's diet.
- The baby's skin is almost always covered with clothing, and direct sunlight is not recommended for children under 6 months due to the risk of burns.
- Sunscreen, which is necessary in the summer, also sharply reduces the production of vitamin D
- In the autumn-winter period, the angle of incidence of solar rays in our latitudes is insufficient for effective synthesis
- Dark skin produces vitamin D much more slowly and requires longer sun exposure
- In premature babies, the supply of vitamin D and minerals accumulated in utero is initially lower
- Rapid growth in the first year of life sharply increases the need for calcium and phosphorus
- Less commonly, the cause is diseases of the intestines, liver and kidneys that interfere with the absorption and conversion of vitamin D, as well as rare hereditary forms
Распространённое убеждение «мы живём в солнечной стране, значит рахита быть не может» на практике не подтверждается. Городской ребёнок значительную часть дня проводит в помещении, гуляет одетым и в коляске с капюшоном, а летом — под кремом и в тени. Всё это правильно с точки зрения защиты кожи, но означает, что витамин D нужно получать дополнительно.
Early Signs: What to Look for
Rickets develops gradually, and its first manifestations concern not the bones, but the well-being and muscles. That is why it is easy to attribute them to the child’s character or teething.
- Restlessness, shallow restless sleep, startling from sounds
- Decreased muscle tone: the child is lethargic, “soft”, later begins to hold his head up, roll over, sit
- Large belly, separation of the rectus abdominis muscles due to weakness of the muscle wall
- Delayed closure of the large fontanel, soft pliable edges of the fontanel and skull sutures
- Flattening of the back of the head and baldness of the back of the head from friction with the pillow
- Late eruption of teeth and disruption of their order, tendency to early caries
- Lumps on the ribs where bone meets cartilage and thickening at the wrists and ankles
- Deformation of the chest, and in a walking child - curvature of the legs in the form of the letter O or X
- Growth retardation, pain in the legs when walking, fatigue
Повышенная потливость, особенно потливость затылка, десятилетиями считалась главным признаком рахита, и до сих пор именно с ней родители чаще всего приходят к врачу. На самом деле потливость сама по себе рахит не подтверждает: у младенцев несовершенна терморегуляция, и потеют они по множеству бытовых причин — от слишком тёплой одежды до жаркой комнаты. Диагноз ставится по совокупности признаков и анализам, а не по влажному затылку.
Who's at risk
- Premature and low birth weight babies
- Breastfed children not receiving vitamin D prophylaxis
- Children born in autumn and winter
- Children with dark skin type
- Children who are rarely outside and who constantly walk completely covered
- Children of mothers who had severe vitamin D deficiency during pregnancy
- Children with rapid growth and significant weight gain
- Children with diseases of the intestines, liver, kidneys, celiac disease and other malabsorption disorders
- Children taking certain anticonvulsants for a long time - as directed by their doctor
- Children on strictly restrictive diets, including no dairy products, no replacement calcium sources
Дефицит витамина D у подростков — тема, о которой говорят реже, но она вполне реальна. Быстрый рост, мало времени на улице, много времени за экранами и однообразное питание создают тот же дефицит, только проявляется он не деформацией костей, а болями в ногах, слабостью мышц и утомляемостью.
Survey
- Осмотр педиатра с оценкой родничка, формы черепа, грудной клетки, запястий, мышечного тонуса и темпов развития.
- Щелочная фосфатаза в крови — повышается одной of первых и служит важным ранним маркером.
- Кальций и фосфор в крови — при рахите фосфор чаще снижен, а кальций может оставаться нормальным за счёт компенсации.
- Уровень витамина D в крови — показывает обеспеченность организма; интерпретирует результат только врач.
- Паратгормон — повышается при длительном дефиците, когда организм вынужден забирать кальций of костей.
- Рентгенография запястья или коленных суставов — назначается при выраженных изменениях и подтверждает диагноз.
- Анализы мочи, оценка функции почек и обследование кишечника — при подозрении на вторичные и наследственные формы.
- Консультация детского эндокринолога — при тяжёлых, рано начавшихся или устойчивых к лечению формах.
Проба Сулковича, которую до сих пор иногда назначают, устарела и не позволяет ни поставить диагноз, ни подобрать дозу. Ориентироваться следует на биохимические показатели крови и заключение врача.
Treatment and prevention
The difference between a preventive and therapeutic dose of vitamin D is fundamental, and it is determined only by a doctor, based on age, weight, test data and the presence of risk factors. There is no point in reading specific dosages on the Internet: they differ significantly for different situations.
- Preventative intake of vitamin D is recommended for children of the first year of life daily and all year round, including the summer months
- Prevention continues in subsequent years - the regimen is determined by the pediatrician
- Children on formula also receive prophylaxis: the doctor takes into account the amount of vitamin supplied with the formula
- If rickets is confirmed, a therapeutic dose is prescribed for a certain period of time, after which they switch to a maintenance dose.
- Sufficient calcium intake from diet: dairy products according to age, and if they are excluded, discuss alternative sources with your doctor
- Walking, daylight and physical activity are useful, but do not replace taking vitamin D
- Age-appropriate massage and gymnastics help muscle tone and motor development
- Control tests at the time prescribed by the doctor to assess the effect and dose adjustment
- Treatment of associated conditions: anemia, intestinal diseases, malabsorption
The opposite caveat is also important: vitamin D is not harmless in large doses. Increasing the dose on your own “just to be sure,” simultaneous taking of several medications with vitamin D, or drops measured by eye from a bottle with a high concentration leads to an overdose. Its signs are vomiting, refusal to eat, thirst, excessive urination, constipation, lethargy and weight loss. The dose is always prescribed by a doctor and measured accurately.
What will happen if left untreated, and is it reversible?
- Early changes - decreased muscle tone, anxiety, laboratory changes - are completely reversible with timely treatment
- Bone deformations that occur at an early age in children under 2 years of age are largely corrected as they grow during treatment.
- Severe leg curvatures that develop in a walking child may require long-term observation by an orthopedist, and in rare cases, surgical correction
- Chest deformation can impair lung ventilation and increase the incidence of respiratory infections
- Deformation of the pelvic bones in girls matters in the distant future
- Rickets is accompanied by delayed motor development and growth, which improve after treatment is started.
- A sharp decrease in calcium can manifest itself as convulsions and spasms of the larynx - this is an emergency condition
- Untreated long-term deficiency increases the risk of tooth decay, poor posture and fractures
Ключевой практический вывод прост: чем раньше начато лечение, тем полнее восстановление. Именно поэтому профилактическая доза витамина D назначается всем младенцам без исключения, а не только тем, у кого уже появились признаки, — предотвратить рахит несопоставимо проще, чем исправлять его последствия.