Vitamin supplementation in healthy patients: What does the evidence support?
This review, with handy tables, summarizes which vitamins offer proven benefits—and which don’t
Vitamin B2
Vitamers: Riboflavin
Physiologic role: Essential component of cellular function and growth, energy production, and metabolism of fats and drugs
Dietary sources: Eggs, organ meats, lean meats, milk, green vegetables, fortified cereals and grains Riboflavin is essential to energy production, cellular growth, and metabolism.2
The takeaway: Its use as migraine prophylaxis has limited data,97 but there is otherwise no evidence to support health benefits of riboflavin supplementation.
Vitamin B3
Vitamers: Nicotinic acid (niacin); nicotinamide (niacinamide); nicotinamide riboside
Physiologic role: Converted to nicotinamide adenine dinucleotide (NAD), which is widely required in most cellular metabolic redox processes. Crucial to the synthesis and metabolism of carbohydrates, fatty acids, and proteins
Dietary sources: Poultry, beef, fish, nuts, legumes, grains. (Tryptophan can also be converted to NAD.)
Niacin is readily converted to NAD, an essential coenzyme for multiple catalytic processes in the body. While niacin at doses more than 100 times the recommended dietary allowance (RDA; 1-3 g/d) has been extensively studied for its role in dyslipidemias,2 pharmacologic dosing is beyond the scope of this article.
The takeaway: There is no evidence supporting a clinical benefit from niacin supplementation.
Vitamin B5
Vitamers: Pantothenic acid; pantethine
Physiologic role: Required for synthesis of coenzyme A (CoA) and acyl carrier protein, both essential in fatty acid and other anabolic/catabolic processes
Dietary sources: Almost all plant/animal-based foods. Richest sources include beef, chicken, organ meats, whole grains, and some vegetables
Pantothenic acid is essential to multiple metabolic processes and readily available in sufficient amounts in most foods.2 Although limited RCT data suggest pantethine may improve lipid measures,12,98,99 pantothenic acid itself does not seem to share this effect.
The takeaway: There is no data that supplementation of any form of vitamin B5 has any patient-oriented clinical benefits.
Continue to: Vitamin B6...
