Writer Sasa Jovenic has examined the signs of vitamin D deficiency and who is at risk. Read on today for the current guidelines on how to advise your patients and consequences of overdosing.

Current guidelines

For starters, the DH recommends all pregnant and breastfeeding women should take a daily supplement containing 10 micrograms (0.01mg) of vitamin D to ensure the mother's requirements for vitamin D are met and to build adequate fetal stores for early infancy.

In addition, all babies and young children aged six months to five years should take a daily supplement containing vitamin D in the form of vitamin drops, to help them meet the requirement set for this age group of 7-8.5 micrograms (0.007-0.0085mg) of vitamin D a day.

Breastfed infants may need to receive drops containing vitamin D from one month of age if their mother has not taken vitamin D supplements throughout pregnancy, but babies fed infant formula will not need vitamin drops until they are receiving less than 500ml (about a pint) of infant formula a day, as these products are fortified with vitamin D.

People should also take a daily supplement containing 10 micrograms (0.01mg) of vitamin D if they are aged 65 years or over, aren't exposed to much sun – for example, those who cover up their skin for cultural reasons – or are housebound or confined indoors for long periods.

Single vitamin D supplements or vitamin drops containing vitamin D (for use by under-fives) are available over the counter, and women and children who qualify for the Healthy Start scheme can get free supplements containing the recommended amounts of vitamin D (see www.healthystart.nhs.uk for more information).

Overdose risk

Taking too many vitamin D supplements over a long period of time – more than 25 micrograms (0.025mg) a day – can cause more calcium to be absorbed than can be excreted. The excess calcium can be deposited in, and damage, the kidneys, and excessive intake of vitamin D can also encourage calcium to be removed from bones, which can soften and weaken them – the opposite of what is trying to be achieved.

Vitamin D toxicity results in symptoms such as feeling and being sick, loss of appetite and frequent urination, but it is uncommon and usually only affects people who have been taking vitamin D supplements well above the recommended dosage for several months.

However, it is worth pointing out to any of your customers considering vitamin D supplementation that some medical conditions – such as kidney or liver disease – can make people more sensitive to the effects of vitamin D, meaning that vitamin D toxicity can happen at a lower level.

As always, it’s a good idea to advise your customer to talk to their GP if they have a history of chronic health conditions and are considering taking any supplements. In more severe cases where the deficiency has affected bone growth and density, such as rickets, a vitamin D injection may be recommended.

Join us tomorrow for the final instalment of our vitamin D deficiency week where we’ll explain the opportunities for further care.