Keratosis pilaris is a common skin condition that presents itself as little red bumps, which are usually found on the upper arms, thighs, cheeks or buttocks. The bumps are painless, dry, and tend to get worse during the drier and colder seasons. The condition is medically harmless, but it can affect how people feel about the appearance of their bodies. Actually, 40% of those with keratosis pilaris have negative views on self-image and it impacts their quality of life. (2)
Source: By Irja from San Francisco (keratosis_pilaris) [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons
The condition is an autosomal dominant disorder and affects about 50-80% of adolescents and about 40% of adults. It often appears during childhood, and then disappears sometime during adulthood. (1)
The cause of the bumps is the buildup of keratin, which plugs and blocks the opening of the hair follicles. Keratin is a strong, fibrous, hard protein that protects the skin cells from damage. Treatments include various creams which remove dead skin cells and/or prevent the follicles from becoming plugged. Unfortunately, the creams often cause redness, stinging and/or skin irritation. I have nothing against medical creams or medicine in general, but if we can avoid putting anything unnatural in or on our bodies by taking more natural approaches, than I am all for that.
How Diet Can Influence Keratosis Pilaris
There is no doubt that diet can influence the health of our skin, and the rest of our bodies for that matter. A lot of nutrient deficiencies can influence skin conditions. However, I had a hard time finding journal articles and hard evidence in favor of specific diet management strategies for keratosis pilaris. That being said, there are three key nutrients that have a large impact on the integrity and health of skin. The three I’ll be talking about are vitamin A, vitamin C, and zinc. With these nutrients, I recommend getting them from food, and avoid supplementation if possible.
Vitamin A
Vitamin A is probably the most well researched nutrient involved in promoting healthier skin. Undoubtedly, you’ve heard of vitamin A or retinol containing anti-aging creams. Natural and synthetic analogs of vitamin A are known as retinoids. Retinoids are involved in embryogenesis, reproduction, vision, growth, inflammation, differentiation, proliferation, and apoptosis. Vitamin A, which is technically retinol, is the active, usable form of vitamin A. Retinol is found in animal foods, particularly in liver. Beta-carotene is found in plant foods like carrots, which our bodies have to convert to vitamin A (retinol) at a conversion rate of 12:1.(3) This means we have to consume more beta-carotene than retinol in order to get enough vitamin A. However, it’s not that hard to consume enough beta-carotene to meet our needs of vitamin A. Be careful with consuming too much retinol though, because in excess, vitamin A (retinol) is toxic. (4)
Topical retinol improves aging skin, but it can cause skin peeling, itching, dryness, and burning. (6)
Retinol and retinyl esters are both found in keratinocytes (skin cells that make keratin), so we know vitamin A is involved in keratin production.(7) In fact, vitamin A deficiency has been shown to lead to dry skin and follicular hyperkeratosis (too much keratin in the follicle).(5) I think it’s pretty convincing that adequate vitamin A intake could improve keratosis pilaris.
The Recommended Dietary Allowances for vitamin A are given as micrograms (mcg) of what’s known as retinol activity equivalents (RAE). Retinol has the highest retinol activity equivalent (RAE). The RAEs are listed below to help you understand and be able to calculate approximately what you should be consuming from different food sources. A lot of the vitamin A found on a food or supplements label is written as International Units (IUs).
- 1 IU retinol = 0.3 mcg RAE
- 1 IU beta-carotene from supplements = 0.15 mcg RAE
- 1 IU beta-carotene from food = 0.05 mcg RAE
- 1 IU alpha-carotene or beta-cryptoxanthin = 0.025 mcg RAE
Recommended Dietary Allowances (RDA) for Vitamin A
Age |
Male |
Female |
Pregnancy |
Lactation |
0–6 months |
400 mcg RAE |
400 mcg RAE |
||
7–12 months |
500 mcg RAE |
500 mcg RAE |
||
1–3 years |
300 mcg RAE |
300 mcg RAE |
||
4–8 years |
400 mcg RAE |
400 mcg RAE |
||
9–13 years |
600 mcg RAE |
600 mcg RAE |
||
14–18 years |
900 mcg RAE |
700 mcg RAE |
750 mcg RAE |
1,200 mcg RAE |
19–50 years |
900 mcg RAE |
700 mcg RAE |
770 mcg RAE |
1,300 mcg RAE |
51+ years |
900 mcg RAE |
700 mcg RAE |
I’ve listed some food sources and the quantities in both IU and mcg RAE below.
Food |
mcg RAE |
IU |
%DV |
Sweet potato, 1 whole |
1,403 |
28,058 |
561 |
Beef liver, 3 ounces |
6,582 |
22,175 |
444 |
Carrots, 1/2 cup raw |
459 |
9,189 |
184 |
Pumpkin pie, 1 piece |
488 |
3,743 |
249 |
Cantaloupe |
135 |
2,706 |
54 |
Red Pepper, 1/2 cup raw |
117 |
2,332 |
47 |
Mangos, 1 whole raw |
112 |
2,240 |
45 |
Apricots, dried, 10 halves |
63 |
1,261 |
25 |
Broccoli, boiled, 1/2 cup |
60 |
1,208 |
24 |
Ice Cream, vanilla 1 cup |
278 |
1,014 |
20 |
Milk, w/ added vitamin A, 1 cup |
149 |
500 |
10 |
Butter, 1 Tbsp |
106 |
355 |
|
Egg, 1 large |
75 |
260 |
As an example, let’s say you’re a 30 year old male, and that means you need 900 mcg RAE every day. You eat a ½ cup of carrots, and it gives you 9,189 IU of beta-carotene. 9,189 IU x 0.05 mcg RAE = 459 mcg RAE. Just from eating a couple carrots you’ve already eaten half of the RDA for vitamin A. It’s not as complicated as it seems.
In my opinion, the Daily Value isn’t as accurate as mcg RAE. The Daily Value was developed by the FDA to make it easier for consumers to compare the nutrient content of different foods. I recommend trying to understand the mcg RAE and IU if possible. If it’s too complicated, then make sure you are least meeting the Daily Value. Again, be careful with consuming too much preformed vitamin A (retinol), (which is the vitamin A from animal sources), because it can be toxic to our bodies if consumed in excess. Also, studies have linked high quantity beta-carotene supplements to having adverse effects as well. Below is how much vitamin A is considered safe, and it’s generally understood that consuming levels above this could potentially have negative health consequences.
Tolerable Upper Intake Levels (UL) for Preformed Vitamin A
Age |
Male |
Female |
Pregnancy |
Lactation |
0–12 months |
600 mcg RAE |
600 mcg RAE |
|
|
(2,000 IU) |
(2,000 IU) |
|||
1–3 years |
600 mcg RAE |
600 mcg RAE |
|
|
(2,000 IU) |
(2,000 IU) |
|||
4–8 years |
900 mcg RAE |
900 mcg RAE |
|
|
(3,000 IU) |
(3,000 IU) |
|||
9–13 years |
1,700 mcg RAE |
1,700 mcg RAE |
|
|
(5,667 IU) |
(5,667 IU) |
|||
14–18 years |
2,800 mcg RAE |
2,800 mcg RAE |
2,800 mcg RAE |
2,800 mcg RAE |
(9,333 IU) |
(9,333 IU) |
(9,333 IU) |
(9,333 IU) |
|
19+ years |
3,000 mcg RAE |
3,000 mcg RAE |
3,000 mcg RAE |
3,000 mcg RAE |
(10,000 IU) |
(10,000 IU) |
(10,000 IU) |
(10,000 IU) |
Vitamin C
Vitamin C is the most abundant antioxidant in skin, and it is a cofactor and essential for collagen biosynthesis and stimulates collagen gene expression. Collagen is actually the most abundant protein found in the body, and its definitely important in maintaining the integrity of skin. Vitamin C also has anti-inflammatory properties, which it does through the inhibition of NFkB. NFkB activates pro-inflammatory cytokines like IL1 and IL6. (8)
Knowing what we know about vitamin C, it’s possible that vitamin C could help with a skin condition like keratosis pilaris.
Recommended Dietary Allowances (RDA) for Vitamin C
Age |
Male |
Female |
Pregnancy |
Lactation |
0–6 months |
40 mg |
40 mg |
||
7–12 months |
50 mg |
50 mg |
||
1–3 years |
15 mg |
15 mg |
||
4–8 years |
25 mg |
25 mg |
||
9–13 years |
45 mg |
45 mg |
||
14–18 years |
75 mg |
65 mg |
80 mg |
115 mg |
19+ years |
90 mg |
75 mg |
85 mg |
120 mg |
A lot of foods contain vitamin C. It’s not that hard to get enough vitamin C in your diet.
Food Sources of Vitamin C
Food |
Milligrams (mg) per serving |
Percent (%) DV* |
Red pepper, sweet, raw, ½ cup |
95 |
158 |
Orange juice, ¾ cup |
93 |
155 |
Orange, 1 medium |
70 |
117 |
Grapefruit juice, ¾ cup |
70 |
117 |
Kiwifruit, 1 medium |
64 |
107 |
Green pepper, sweet, raw, ½ cup |
60 |
100 |
Broccoli, cooked, ½ cup |
51 |
85 |
Strawberries, fresh, sliced, ½ cup |
49 |
82 |
Brussels sprouts, cooked, ½ cup |
48 |
80 |
Grapefruit, ½ medium |
39 |
65 |
Broccoli, raw, ½ cup |
39 |
65 |
Tomato juice, ¾ cup |
33 |
55 |
Cantaloupe, ½ cup |
29 |
48 |
Cabbage, cooked, ½ cup |
28 |
47 |
Cauliflower, raw, ½ cup |
26 |
43 |
Potato, baked, 1 medium |
17 |
28 |
Tomato, raw, 1 medium |
17 |
28 |
Spinach, cooked, ½ cup |
9 |
15 |
Green peas, frozen, cooked, ½ cup |
8 |
13 |
Although vitamin C is regarded as a fairly safe nutrient (even in supplemental form), there are upper limits for vitamin C, meaning that you shouldn’t take more than this amount. Taking more than the upper limit isn’t safe and could have negative impacts on your health.
Tolerable Upper Intake Levels (UL) for Vitamin C
Age |
Male |
Female |
Pregnancy |
Lactation |
0–12 months |
Not possible to establish* |
Not possible to establish* |
||
1–3 years |
400 mg |
400 mg |
||
4–8 years |
650 mg |
650 mg |
||
9–13 years |
1,200 mg |
1,200 mg |
||
14–18 years |
1,800 mg |
1,800 mg |
1,800 mg |
1,800 mg |
19+ years |
2,000 mg |
2,000 mg |
2,000 mg |
2,000 mg |
Zinc is the last nutrient that I’ll be very briefly discussing. Zinc plays a role in the normal function of skin, and has been shown to provide benefits for many skin conditions.(10) Zinc also helps with wound healing.(11) Meat is generally where most people get their zinc. Nuts, seeds, and legumes also contain some zinc.
RDA for Zinc
Age |
Male |
Female |
Pregnancy |
Lactation |
0–6 months |
2 mg* |
2 mg* |
||
7–12 months |
3 mg |
3 mg |
||
1–3 years |
3 mg |
3 mg |
||
4–8 years |
5 mg |
5 mg |
||
9–13 years |
8 mg |
8 mg |
||
14–18 years |
11 mg |
9 mg |
12 mg |
13 mg |
19+ years |
11 mg |
8 mg |
11 mg |
12 mg |
Food Sources of Zinc
Food |
Milligrams (mg) |
Percent DV* |
per serving |
||
Oysters, cooked, breaded and fried, 3 ounces |
74 |
493 |
Beef chuck roast, braised, 3 ounces |
7 |
47 |
Crab, Alaska king, cooked, 3 ounces |
6.5 |
43 |
Beef patty, broiled, 3 ounces |
5.3 |
35 |
Breakfast cereal, fortified with 25% of the DV for zinc, ¾ cup serving |
3.8 |
25 |
Lobster, cooked, 3 ounces |
3.4 |
23 |
Pork chop, loin, cooked, 3 ounces |
2.9 |
19 |
Baked beans, canned, plain or vegetarian, ½ cup |
2.9 |
19 |
Chicken, dark meat, cooked, 3 ounces |
2.4 |
16 |
Yogurt, fruit, low fat, 8 ounces |
1.7 |
11 |
Cashews, dry roasted, 1 ounce |
1.6 |
11 |
Chickpeas, cooked, ½ cup |
1.3 |
9 |
Other Natural Remedies
These remedies are taken from the Mayo Clinic (12) and should be used in conjunction with getting adequate nutrients in your diet.
- Don’t take long hot showers. Hot water removes the natural oils on our skin which help to keep it hydrated and protected. Take warm showers (or cool/cold if you can handle it) for a duration of less than 10 minutes.
- Don’t use strong soaps. Find a gentle soap. Exfoliate with a loofa or wash cloth to remove dead skin cells. Scrubbing too hard or too much may irritate the skin and might make it worse. After the shower, gently pat dry; don’t scrub dry.
- Apply lotion while the skin still contains some moisture from bathing. Also, you should continue to apply lotion a few times a day, not just after a shower.
- Use a humidifier in your house during the drier, colder months of the year. There are portable ones or ones that you can attach to your furnace to add moisture to the air.
- Friction from tight fitting clothes can irritate the skin as well, so don't wear clothing that's too tight.