This site is intended for health professionals only

Tackling vitamin D deficiency

Good nutrition is crucial to good health, particularly at the time of pregnancy, childbirth and lactation. Although there are not large numbers of starving mothers in the UK, it is important to try to achieve optimal nutrition at this period of a woman's life.

It has been found that low levels of vitamin D are common in mothers and infants in Britain and these low levels have many effects on their health. For instance, since the 1990s, hospital services for children have all reported increases in patients with rickets, seizures and muscle weakness. These cases are the most dramatic tip of a large iceberg of insufficiency of vitamin D. It is reasonable to suspect many infants and children have milder deficiencies that do not lead them to hospitals or for blood tests, but probably cause milder problems in their families and local communities.1,2

Many mothers, too, have low vitamin D levels. Some from 'at risk' groups are more likely to suffer vitamin D deficiency, such as those with a dark skin, those that wear traditional clothing or those with twin pregnancies. However now that most adults use sunblock creams, and as many cosmetics include these, many mothers outside these groups will not have good levels of vitamin D when they become pregnant.3

It is useful to have a working knowledge of this vitamin as a community nurse or health visitor, as three specific groups of individuals need more vitamin D than most - the pregnant mother, the lactating mother and infants. Their requirements are high, as they all have to take in larger amounts of calcium from their diet and create bone growth or produce milk.  

What is vitamin D and how is it used?

We need small amounts of vitamins regularly in order for metabolism to function.  These were named early in the last century. Vitamin D is unusual as it is found in fat and comes from two sources. Firstly it is made in our skin after exposure to sun.  Secondly it is also absorbed from a number of foods - fish, mushrooms and eggs contain vitamin D. This vitamin is not found in fruit or vegetables in high levels.  

Vitamin D is needed to absorb calcium from the bowel. Without it, calcium levels in the blood will tend to fall. Calcium can then be moved out of the bones to compensate - the bones will then become softer and weaker. In children this causes rickets, and in adults, such as the pregnant mother, it causes osteomalacia. Low levels of vitamin D can also result in muscle weakness, and this may delay walking in toddlers. In teenagers and adults it may cause complaints of muscle aches or pain.4

Low levels of vitamin D may lead to many problems outside the skeleton. It is likely that low levels of vitamin D can aggravate wheezing and chest infections in babies. It can aggravate hypertension in pregnancy or predispose an individual to contracting tuberculosis. Achieving a reasonable intake of vitamin D is therefore a particularly good public health aim as it is likely to reduce many problems and pathologies in clients of all ages.5

The sun and vitamin D

Human beings require sunshine. Like plants we have a number of metabolic processes that need the energy from our nearest star. One of the main effects of sunshine on our skin is to produce vitamin D. Living in Britain, a very northerly island, few ultraviolet rays reach us. The sun is unlikely to provide enough energy to make vitamin D in our skin between October and March. If a sunblock compound is used, very little vitamin D will be made in the skin. 

The skin has a system for ensuring that only sufficient vitamin D is made - one cannot overdose on vitamin D through the skin. This is different to the vitamin D taken in the diet, perhaps as a supplement. It is possible to take too much vitamin D by mouth - this is rare however, and supplements and foods have directions as how best to use them and at what dose. 

How you can help

If we are to improve this nutritional problem the best place to start is in the community. The problem cannot be solved in hospitals. Community nurses and health visitors manage some of the most vulnerable with respect to vitamin D: the lactating mother and newborn infant. A number of services around the UK have found that health visitors working in communities are particularly effective in improving vitamin D levels and other aspects of nutritional status in infants.2

Check your clients and patients

It is worth reviewing your patients and clients to determine how much sunshine actually reaches their skin. Sunshine exposure is limited by lifestyle, clothing, by skin colour - darker skins require more ultraviolet light, in general - and the use of ultraviolet barrier creams. Just as sunshine enables the skin to make vitamin D, it also leads to ageing signs in that skin. Many cosmetics and skin protective agents will therefore block ultraviolet and reduce our ability to make vitamin D. As a result, it is not only the second-generation Jamaican mother-of-three who may be deficient, but also the careful Scottish teacher using sunblocks and anti-ageing creams.  

Who needs extra?

Some of those you work with require more vitamin D than others. Those who are growing fast, and making bone and muscle tissue will need more of this vitamin, as mentioned. Pregnant mothers, lactating mothers and infants require more vitamin D. If a mother has twins, or has had several infants before, she is more likely to require a supplement than a first time mother. 

Adolescents require vitamin D too for the same reasons. Current lifestyles for many in this age group means their exposure to sun is small and diets will not contain much vitamin D.3 Some specific groups of individuals, such as the obese or those on antiepileptic medication, also require more vitamin D.

Food sources of vitamin D

Although the skin is the main source of vitamin D, it is absorbed from food or supplements too. This was one of the reasons for the success of cod liver oil supplements in Victorian times, although then the reasons for its benefits were not clear. When food was rationed in World War II, the rations were designed to ensure that all had sufficient vitamin D. Oily fish are a good source, and eggs contain reasonable levels of vitamin D too, as most chickens receive it in their feed. Some cereals and other foods are supplemented. However dietary sources can be expensive or unpalatable; recommending a vitamin supplement may be good practice for many clients and patients.

A daily multivitamin is required for all children from birth until the age of five years.  A daily vitamin supplement (such as in the 'Healthy Start' pills) is recommended for pregnant and lactating mothers. Guidelines for supplements can be found in the National Institude for Health and Care Excellence (NICE) guideline for antenatal care, the British National Formulary (BNF) for children and the local commissioners guideline for vitamin D supplementation.  

Are blood tests needed?

It is rare for a blood test to be required. Although it might be useful to have a figure to hand of a blood level of vitamin D, blood tests can be difficult to arrange and are expensive. They also are traumatic for infants. A reasonable assessment of vitamin D status can be usually put together by looking at the sunshine exposure and the diet of a particular individual. When in doubt, check with the general practitioner, a local pharmacist or the local paediatric service for recommendations. Remember: no harm results from taking a daily dose of a routine multivitamin. In this article, no specific doses have been mentioned - these are available in the references outlined below.

Some practical ideas

A number of strategies might be helpful:

 - Give Healthy Start application packs to all women at registration booking.

 - Ensure all infants receive a multivitamin supplement in the form of drops from birth until five years of age.

 - Discuss vitamin D-rich diets for mothers, particularly if lactating, and weaned infants.

 - If mothers or families are not eligible for Healthy Start, inform them of the importance of purchasing multivitamins from the community chemist.

 - Discuss vitamin D with all members of a family if possible - teenagers and fathers can suffer deficiency too.

Many hospital-based services have found that vitamin D deficiency is more common in specific families. For instance, a toddler with vitamin D deficiency is highly likely to have a mother who is also deficient. Mothers who are deficient in vitamin D are often also deficient in iron and might not comply well with folic acid supplements.  There are therefore likely to be specific target families in any practice that would greatly benefit from advice. The most at-risk families might not necessarily be the most poor in socio-economic terms. They are more likely to be those with the most poor health literacy - those that do not know how to work with or access healthcare systems and professionals for reasons of culture, language or deprivation.2



Healthy Start

Royal College of Paediatrics and Child Health

National Osteoporosis Society



1. Pearce S, Cheetham TD. Diagnosis and Management of Vitamin D Deficiency. BMJ 2010;340:b5664.

2. Michie C, Bangalore S. Managing vitamin D deficiency in Children.  London Journal of Primary Care 2010;3:1-6. 

3. Salmasi H, Joshi A, Gediye A, Michie CA. Vitamin D in adolsescents, the parents of tomorrow. W L Med J 2011;3(4):23-28. 

4. Shaw NJ, Mughal MZ. Vitamin D and child health part 1 (skeletal aspects). Arch Dis Child 2013;98(5):363-7.

5. Shaw NJ, Mughal MZ. Vitamin D and child health: part 2 (extraskeletal and other aspects). Arch Dis Child 2013;98(5):368-72.