Could a lack of vitamin D and rickets cause your child's delays in walking?

Soft and pliable bones typically result in bow legs, a disorder that can make walking harder for toddlers. Besides rickets, bow legs are often caused by Blount’s disease. Contrary to the popular belief that overuse of a baby walker can cause bow legs, it’s not true.

Rickets is treatable if detected on time — children usually recover and walk well within five months after the treatment, but if left untreated, rickets can lead to permanent bone deformities. [1]

What causes rickets in children?

Rickets is a disease that results in soft and pliable bones. It is mostly caused by a lack of vitamin D, but it can be due to lack of calcium, and phosphate. Even though rickets is rare nowadays, some children still get it mostly because of bad nutrition or lack of sunlight.

Because calcium and phosphate are crucial elements of a bone, if the availability of calcium is for some reason diminished, phosphate levels are disturbed as well [2]. If a child’s calcium intake is limited, supplementing with Vitamin D alone might not help in prevention or treatment of rickets. [3]

Sunlight is crucial for getting enough vitamin D, but for infants — who are particularly vulnerable to vitamin D deficiency and rickets — vitamin D supplements are the best solution, and are recommended to be given to all children within the first year of life by most pediatricians across the world, especially for babies living at higher latitudes. [4]

Studies have found that many people in Sweden, especially adolescents, are often vitamin D deficient, even during the summer months. This is why most Scandinavians take vitamin D supplements on a daily basis. [5, 6]

Breast milk and Vitamin D

Vitamin D content in the breast milk depends on maternal vitamin D status and in most cases it’s quite low, unless the mother is taking supplements. According to studies, breast milk provides <25 IU/L to 78 IU/L, which is quite low.

Infants' requirements for vitamin D can't usually be met by breast milk alone. The American Association of Pediatricians recommends supplementing your baby’s diet with 400 international units (IU) of vitamin D per day beginning in the first two months after a child is born.

Studies suggest that supplementing with vitamin D prevents rickets, but more research on this is needed. [7, 8] In most of Europe, supplementing starts two weeks after birth. The U. S. and Canada mandate that all infant formulas are fortified with vitamin D: 40–100 IU/100 kcal in the U. S. and 40–80 IU/100 kcal in Canada. [9]

Note: Recommended intake is not the same thing as requirement. Requirement is the lowest amount of a nutrient needed to preserve our health and avoid physical and physiological changes that might affect us. Recommended daily intake is the amount of a nutrient that can meet the requirements and maintain good health in already healthy individuals. [10]

There's a rule of thumb that vitamin D supplements should be taken only in those months that contain the letter "R“. It makes sense because all the months without this letter are spring and summer months, when there's enough sunlight outside, but when it comes to children and their health, do nothing on your own and always check the facts with your pediatrician.

Natural sources of vitamin D

Vitamin D can be a hormone synthesized from the skin after sun exposure, and also a nutrient that we eat — they can’t be distinguished chemically. When it comes to vitamin D as a nutrient, it can be obtained from dietary sources such as eggs, cod liver and other oily fish, vitamin D fortified foods such as margarine or dairy products, and some cereals. [11]

Both ergocalciferol (vitamin D₂) and cholecalciferol (D₃) are dietary supplements. The main difference is that D₂ is obtained from plant sources (such as fungi), and vitamin D₃ originates from animal sources such as lanolin (sheep's wool).

Rickets does cause delays

Rickets is mainly characterized by malformation of the bones, bone pain, and delayed walking. In a group of 42 non-walking toddlers, the delay in walking was caused by rickets in 60 percent of children in the group. [1]

If your child is healthy and doesn't walk, do not worry — some children are naturally lazier and uninterested in moving around. Avoid using a baby walker as it is proven to delay walking, contrary to the common belief that it may speed up the process. [12]

It's extremely important to supplement your infant with vitamin D to prevent rickets and any walking obstructions and delays that come with the disease.

A study conducted on children under two years in Finland concluded that tripling the dose of vitamin D (1200 IU) can't increase bone strength any better than the standard dose. [13] It's best to follow your pediatrician's guidelines on how much vitamin D to give, because they're specific for the region where you live, the period of a year, and of course — your child's needs.