Table 3.

Guidance on screening and supplementation of micronutrients.^9,11,12

Guideline	Recommendation
Blood tests (related to nutritional deficiencies)	1) Blood tests to be repeated every trimester should include: haematinics, calcium, vitamin D, phosphate, PTH, magnesium, vitamin A 2) Monitor vitamin E, zinc, copper and selenium in the first trimester 3) Vitamin K and E levels in women who had long-limb bypass or BPD/DS surgeries
Multivitamin	1) After all bariatric surgery procedures, a daily complete multivitamin and mineral supplement needs to be taken, which needs to continue throughout preconception and pregnancy and should include:  a. thiamine, iron, zinc, copper and selenium, folic acid, thiamine, vitamin B12, vitamin D, vitamin E and vitamin A in the form beta-carotene.  b. pregnancy-specific micronutrient supplements are needed in pregnancy.
Vitamin A	1) Vitamin A in the form of retinol needs to be avoided during pregnancy, due to its teratogenicity risk. 2) Replace this with beta-carotene, included within the multivitamin.
Folic acid	1) Women should start 0.4 mg folic acid preconception and throughout the first trimester to reduce the risk of neural tube defects. 2) Women who have a BMI of >30 kg/m2 or with pre-existing diabetes will need 5 mg folic acid.
Thiamine and vitamin B	1) If there is prolonged vomiting, there is risk of thiamine deficiency. 2) Prescribe 200–300 mg thiamine with vitamin B complex. 3) Intravenous replacement may be needed in severe cases, typically in the form of Pabrinex.

All other micronutrients need to be monitored and supplemented according to need.