Minerals/vitamins

The optimal supplementation of vitamins and minerals is
not really known for patients with ESRD on dialysis who have also had
bariatric surgery. However, in March 2008, the American Society for
Metabolic and Bariatric Surgery (ASMBS) published nutrition guidelines for
the surgical weight loss patient.This paper addressed optimal methods
for nutrition assessment of pre- and post-weight loss surgery patients.
Supplementation guidelines for vitamin/minerals for the three most common
types of weight loss surgery were provided based on studies available at the
time. Specific recommendations for patients following sleeve gastrectomy
were not given. The article stated, “As advances are made in the field of
bariatrics and nutrition, updates regarding supplementation suggestions are
expected.”Later that same year, a retrospective study of 137 RYGB
patients published in the American Journal of Clinical Nutrition Studies
concluded that nutritional deficiencies following bariatric surgery cannot
be prevented by provision of a standard multiple vitamin preparation.

In several studies, deficient levels of vitamins and minerals have been
found in patients prior to bariatric surgery. Vitamins identified included
vitamin B12, folate, vitamin A and vitamin D (25 OH). Minerals that were
deficient included zinc, ferritin (iron stores), selenium, and magnesium.
Additionally, low levels of albumin and hemoglobin have also been identified
preoperatively. These same nutrients were frequently deficient at one year
postoperatively, but many were improved compared to preoperative
levels.

Most weight loss surgery patients are told to take a “good” multivitamin
with mineral supplement. Some nutrients have commonly been supplemented at
higher levels than found in a multivitamin, including iron, vitamin B12, and
calcium. Vitamin D is also frequently supplemented at higher than
recommended dietary allowance (RDA). Deficient nutrients that have been
previously under-recognized include copper, magnesium, thiamine, zinc,
vitamin K, and vitamin B6.

Multiple vitamin and mineral supplements vary greatly. Standard chewable
forms may not be as “complete” as nonchewable multiple vitamins with
minerals. It is necessary to compare products, especially as new products
developed specifically for weight loss surgery patients are being developed.
Dietitians should know the contents of the supplements taken and look for
any nutrients provided in insufficient amounts.
Vitamin D. Vitamin D has been a hot topic among researchers for a number of
years. It is now recognized that patients with obesity are more likely to
have insufficient serum 25 OH vitamin D. Many patients are already deficient
in vitamin D at the time of weight loss surgery.
Hypovitaminosis D and bone loss are common in patients after gastric bypass.
In one study, to correct the serum 25 OH levels, the mean supplementation
provided was 6,472IU of vitamin D per day.31 However, the Institute of
Medicine released Dietary Reference Intakes for Calcium and Vitamin D,
2011.32 It suggested the upper safe level for vitamin D is 4,000 IU/day.
This recommendation was made for the general “healthy” population and not
specific to patients with obesity. In fact, the report does note that serum
levels of vitamin D are frequently low in individuals with obesity.

This fat-soluble vitamin can be difficult to replete and maintain adequate
levels. Serum 25-OH D3 may rise by 1ng/mL for every 100IU of additional
vitamin D provided. Some studies indicate that vitamin D3 (cholecalciferol),
derived from animal or microbial sources, is more effective for repletion
that provision of vitamin D2 (ergocalciferol), which is derived from plants.
Optimal 25-OH D3 levels are thought to be greater than 32ng/mL.[33]
Obtaining serum 25 OH vitamin D levels is the best way to know if the amount
of vitamin D being supplemented is adequate.

Patients with ESRD are no longer able to convert 25 OH vitamin D to its
active form (1-25 OH vitamin D). Routine supplementation of vitamin D (D3 or
D2) in patients with ESRD on dialysis was not common due to the assumption
that supplementation of either form of vitamin D would result in
hypercalcemia. Supplementation with vitamin D3 in order to replete 25 OH
vitamin D levels does not cause hypercalcemia. Adequate 25 OH vitamin D
levels are required to maintain normal parathyroid hormone (PTH)
levels.In addition, restoring vitamin D to normal range may also
have an epoetin-sparing effect.

Hemodialysis patients with vitamin D deficiency who were not supplemented to
reach normal levels had a higher incidence of mortality compared to those
who were supplemented, and had the highest serum 25 OH vitamin D or 1,25 D
levels.

Signs of vitamin D insufficiency or deficiency are not obvious. Rickets and
osteomalacia are two bone-related deficiency conditions. Other signs may be
more subtle, including muscle pain or arthritis pain. In the elderly
population, muscle weakness and cognitive impairment have been improved by
increased vitamin D intake