All about fruitarianism with a long-term fruitarian, Lena

Vitamin B12 bioavailability significantly decreases with increasing intake of this vitamin per meal. Vitamin B12 is partially degraded and loses its biological activity during cooking and storage of foods.

The intrinsic factor-mediated gastrointestinal absorption system in humans has evolved to selectively absorb active vitamin B12 from naturally occurring vitamin B12 compounds, including its degradation products and inactive corrinoids.  This absorption system is estimated to be saturated at about 1.5 - 2.0 mcg of cobalamin (B12) per meal, 50% of dietary vitamin B12 is absorbed by healthy adults with normal gastro-intestinal function.

Some plant foods, dried green and purple lavers (nori) contain substantial amounts of vitamin B12, although other edible algae contained none or only traces of it. Most of the edible blue-green algae (cyanobacteria) used for human supplements predominantly contain pseudovitamin B12, which is inactive in humans.

The bioavailability of vitamin B12 in healthy humans from fish meat, sheep meat, and chicken meat averaged 42%, 56%-89%, and 61%-66%, respectively, in eggs it seems to be poorly absorbed (< 9%).

John Stuart Mill

A person may cause evil to others not only by his actions but by his inaction, and in either case he is justly accountable to them for the injury.

Zinc

Zinc is a nutritionally essential mineral needed for catalytic, structural, and regulatory functions in the body.

The RDA (recommended daily allowance) for adult women and men is 8 mg a day and 11 mg a day of zinc, respectively.

Severe zinc deficiency is a rare, genetic or acquired condition. Dietary zinc deficiency, often called marginal zinc deficiency, is quite common in the developing world, affecting an estimated 2 billion people. Zinc deficiency can cause impaired growth and development in children, pregnancy complications, immune dysfunction, and increased susceptibility to infections. Long-term consumption of zinc in excess of the tolerable upper intake level of 40 mg a day for adults can result in copper deficiency.

Zinc bioavailability is relatively high in meat, eggs, and seafood. Zinc is less bioavailable from whole grains and legumes due to the inhibitory effects of phytic acid on absorption of the mineral.

Fruitarians.net Apple