Calcium and Albendazole Supplementation in Pregnancy
On this page
Direct answer
Calcium and albendazole are two supplements given in pregnancy for distinct purposes. Calcium reduces the risk of pre-eclampsia where dietary intake is low, and albendazole treats soil-transmitted helminth infection. Albendazole is given as a single dose after the first trimester, preferably in the second, and is avoided in the first trimester.
What you must remember
- Calcium indication: low dietary calcium is the setting in which supplementation has its strongest evidence for reducing pre-eclampsia.
- High-dose calcium: WHO recommends a high daily dose of about 1.5 to 2 g where dietary calcium is low; India's MoHFW guideline uses a lower dose of about 1 g elemental calcium daily (500 mg twice daily) with vitamin D, so current MoHFW guidance is checked for the exact regimen.
- Calcium and iron: calcium reduces iron absorption when taken together, so the two are given at different times of the day.
- Albendazole dose: a single 400 mg dose during pregnancy, as set by national deworming guidance.
- Timing: avoided in the first trimester, with the second trimester preferred and the dose given after organogenesis.
- Evidence for deworming: trials show no clear effect on maternal anaemia in the third trimester, so the case rests on infection control and programme goals.
- Side effects: nausea, vomiting, rash and abdominal discomfort are the usual adverse effects, and serious reactions are uncommon.
A decision sequence for calcium and deworming at antenatal visits
At each antenatal visit the clinician checks diet, gestation and infection risk before prescribing either supplement. The steps below place both drugs in the right window and avoid the common errors in timing. Calcium and deworming decisions are made at the same visit, which is why the order matters.
- Assess dietary calcium: a low intake signals the setting where calcium supplementation has the strongest evidence.
- Start calcium on the programme schedule: dose and start point follow current national guidance, with WHO's high-dose regimen applying to low-intake settings.
- Separate calcium from iron: the two are given a few hours apart so that iron absorption is protected.
- Check gestation before albendazole: the drug is not given in the first trimester under any circumstances.
- Give a single albendazole dose: 400 mg after the first trimester, preferably in the second, as per national guidance.
- Reinforce hygiene: handwashing and safe water are advised, since reinfection is common in endemic areas without sanitation.
Where the exam tries to catch you
Vignettes test the gestational timing of albendazole, the interaction between calcium and iron, and the strength of the evidence for deworming.
- Trap: Giving albendazole in the first trimester because the woman has worms. Correct: It is avoided in the first trimester, and the second trimester is preferred.
- Trap: Taking calcium and iron together to save a visit. Correct: Calcium impairs iron absorption, so the two are separated in time.
- Trap: Claiming deworming clearly lowers maternal anaemia. Correct: Trial evidence shows no clear effect on third-trimester anaemia, so the rationale rests on infection control and programme grounds.
Frequently asked questions
What is the main indication for calcium supplementation in pregnancy?
Calcium supplementation is indicated mainly to reduce the risk of pre-eclampsia in women with low dietary calcium intake. The high-dose regimen is recommended in that setting. Its benefit is weaker where dietary intake is adequate.
Why is albendazole avoided in the first trimester?
Albendazole is avoided in the first trimester because of concern about fetal exposure during organogenesis. National guidance therefore gives it after the first trimester, preferably in the second. This timing is a point examiners frequently test.
Does albendazole improve anaemia in pregnant women?
Trial evidence does not show a clear effect of a single antihelminthic dose on maternal anaemia in the third trimester. The rationale for deworming rests mainly on infection control and programme goals. Results vary between studies.
Why should calcium be separated from iron in pregnancy?
Calcium reduces the absorption of iron when the two are taken together. Calcium and iron tablets are therefore given at different times of the day. This keeps iron absorption adequate for treating anaemia.