Summary of guidelines for the supplementation and blood monitoring for patients following bariatric surgery

Lifelong nutritional supplementation

Following a gastric bypass and sleeve gastrectomy:

  1. Forceval capsule, 1 twice daily (on prescription)
  2. Adcal D3, 1 twice daily or Theical-D3 half tablet, twice daily (on prescription)
  3. Ferrous gluconate, 300mg daily (on prescription)
  4. Vitamin B12 (hydroxycobalamin) 1mg 3 monthly, start 6 months post op (IM injections at GP surgery)
  5. Thiamine (vitamin B1) 50-100mg daily (patient to purchase over the counter) – first 2 years post-op only. Continue/restart if high risk.
  6. Vitamin D 25mcg, 1 twice daily (patient to purchase over the counter)

Following a gastric band:

  1. Forceval capsule, 1 daily (on prescription)
  2. Adcal D3, 1 twice daily or Theical-D3 half tablet, twice daily (on prescription)
  3. Thiamine (vitamin B1) 50-100mg daily (patient to purchase over the counter)  first 2 years post-op only. Continue/restart if high risk.
  4. Vitamin D 25mcg, 1 twice daily (patient to purchase over the counter)

Please contact us for alternative advice if any of these preparations are contraindicated for your patient.

Please refer to the full guidelines and patient information leaflet for guidance on the use of alternative products.

Planning or during pregnancy

  • We advise to plan pregnancy after 12-18 months of the operation, ideally once weight has stabilised.
  • 5mg folic acid (on prescription) for at least 3 months pre-conception and up until the 13th week of pregnancy.
  • Those who have had a sleeve gastrectomy or gastric bypass should reduce their multivitamin, mineral and trace element (complete A-Z) supplement to one a day and ensure vitamin A is in beta carotene form (Forceval capsule is fine).
  • All other supplements should remain the same unless advised otherwise.

Lifelong nutritional monitoring

We recommend the following routine nutritional blood tests as part of the shared care model for chronic disease management. More frequent monitoring may be necessary until stable and/or corrected.

Gastric bypass, sleeve gastrectomy and gastric band – Every 3 months in the first year, yearly thereafter:

  • Full blood count
  • Urea and electrolytes
  • Phosphate and magnesium
  • Liver function tests
  • Ferritin
  • Folate
  • Vitamin B12 (serum MMA recommended if available, consider history of B12 deficiency or pre-existing neuropathy)
  • Calcium
  • Parathyroid Hormone (PTH)

Gastric bypass, sleeve gastrectomy and gastric band – 6-12 monthly in the first year, yearly thereafter:

  • 25(OH) Vitamin D

Gastric bypass only – Once in the first year, yearly thereafter:

  • Zinc
  • Copper
  • Vitamin A

Somerset GPs: You can order blood tests on order comms via: Test Groups/ Bariatric Surgery/ Bariatric: Band or Bariatric: Bypass or Bariatric: Sleeve

We recommend the following extra routine tests as per individual need:

  • If diabetes pre-surgery or clinically indicated: HbA1c (consider fasting glucose if anaemia) 6-12 monthly.
  • If known dyslipidaemia or concerns re. lipids: Fasting lipid profile 6-12 monthly
  • If low ferritin or clinical concern despite normal ferritin: Transferrin saturation

We recommend the following additional nutritional bloods if there are clinical concerns about poor nutrition or lack of supplementation (please refer to our full guidelines for details on clinical indicators for tests):

  • Vitamin A
  • Vitamin E
  • Vitamin K (INR)
  • Zinc & copper
  • Selenium

Somerset GPs: You can order these on Order Comms via Test Groups/ Bariatric Surgery/ Bariatric: Nutritional Concern:

Planning or during pregnancy

Those who are planning a pregnancy should have their routine and additional nutritional bloods tested (as above)

  • Routine nutritional blood tests should be checked
  • at least twice during pregnancy
  • 3 months postpartum
  • 3 monthly whilst breastfeeding.

Somerset GPs: You can order blood tests on order comms via: Test Groups/ Bariatric Surgery/ Bariatric: Preconception/ pregnancy

Interpretation of results/treatment of abnormal profiles

We are happy to advise on the interpretation of results and management of nutritional concerns. Please direct queries to the Bariatric Dietitians (01823 343394 or bariatricsurgerydietitians@tst.nhs.uk)